What's the limitation of Chimistry? The writing is pretty unhelpful.

[MyWifeIsScary]

It's really unhelpfully worded.
In V20, the first power allows you to create a "static image" but actually gives examples of transitions like glass breaking or a photograph (which presumably you can pick up, right?)

You can provide tactile illusions (invisible walls is a stated example) but obviously tactile illusions need to be hidden or attached to something real.

Using later powers, If I wanted to make long, illusory hair, could I brush my hand through it? If I made a machinegun, could it give the illusion of weight or moving parts? A mirror works, right? Whatabout applying spectacular chimerical makeup to boost appearance?

IDK this power seems like either TheGreatestThing or an expensive waste depending on interpretation.

[Baaldam]

It's really unhelpfully worded.
In V20, the first power allows you to create a "static image" but actually gives examples of transitions like glass breaking or a photograph (which presumably you can pick up, right?)

You can provide tactile illusions (invisible walls is a stated example) but obviously tactile illusions need to be hidden or attached to something real.

Using later powers, If I wanted to make long, illusory hair, could I brush my hand through it? If I made a machinegun, could it give the illusion of weight or moving parts? A mirror works, right? Whatabout applying spectacular chimerical makeup to boost appearance?

IDK this power seems like either TheGreatestThing or an expensive waste depending on interpretation.

Well, i tend to compare Chimerstry to equivalent Obfuscate levels when it comes to trying to estimate a degree of imersion in illusion.
Yes, rough and vague, but at least helps with gauging some benchmarks for players & ST to negotiate a basis they are confortable with.

[Trassel]

I believe the shattered glass refers to sound, as the first level can only affect one sense. A photograph refers to something visible, it would crack under touch.

The powers disperse when proved unreal by a single person, making the powers rather weak used on the fly. Preparation or distractions are probably the strongest uses.

You can brush your hair through the hair, but anyone else doing it would likely break it because it does not feel right. Put in hair extenders and then change color and it would work fine.
Unsure what you mean about weight. Created from nothing, it would just feel odd and break as someone held it. Mask a lead pipe or something, and it would feel more right. You could program it to move and do things, but it requires either focus or a pre-meditated program using level 4.
A mirror is sort of strange. I do not think it works, but you could put the illusion over an existing mirror to make whoever is in-front of it appear as a Lasombra, even though the angles it reflects are probably giving the mirror away.
Spectacular makeup sounds right up its alley.

It is a power that require some foresight. It is easier to make a dollar bill appear as a hundred dollar bill because they feel the same, have the same size and so on than conjuring one up in thin air.

The discipline is fundamentally opposite of obfuscate, it adds instead of removes.

[Karos]

You're fundamentally running into a core problem of illusion based powers in roleplaying games. I.E. how do you deal with something that fundamentally warps perception, something that means the information the characters and players operate with doesn't align with reality.

Obfuscate is easy because it's generally rather limited and focused effects. It's easy to get your head around the constrained idea of a person being invisible and yet still being there.

Something like Chimistry gets weird however, because you're adding something to another's perceptions, which can have a big impact. A canny player who's content to rules lawyer can swing some pretty insane interpretations with a lenient ST, in no small part due to the design of the powers. The writers had to leave room for players to improvise and describe the illusions they create, otherwise, the powers aren't as useful. The more restrictions placed upon them the easier they are to understand and to interact with as an ST or another player. But at the same time, the less versatile, engaging, and useful they become for the player using them.

At the end of the day if Chimistry powers are on the table for players I'd agree their effects as a table upfront to the greatest degree possible. You'll never get a perfect consistent ruling straight from the book, so settle on something your table can abide by. (Can it act like a mirror, does the hair feel real, etc.) After that point, stick with the definition and only change it following a frank and open discussion.

[MyWifeIsScary]

You're fundamentally running into a core problem of illusion based powers in roleplaying games. I.E. how do you deal with something that fundamentally warps perception, something that means the information the characters and players operate with doesn't align with reality..

You're sitting at a table playing "Let's pretend". It's not that much of an extension from the usual detachment from reality players must put themselves in to control their usual somewhat-racist undead slaying protagonists. VTM even has the advantage in that Chimestry is a five-power line of progression with each level achieving more than the last. It's not terribly difficult to write proper rules for how this works.

[Rhywbeth]

I read it this way;
Chimestry, going by its name, effects and the opinions of the fey, is the Changeling crossover discipline. It creates chimera, which are dispelled by banality (when the mortals find a way to convince themselves the chimera can't possibly exist). Following the trickster and fairytale themes, it's a sort of riddle-type discipline. You have to prove it's not real, possibly while the Ravnos counters with explanations about how it totally is.

Ignis Fatuus:
Affects a single sense to a radius of 20 cubic feet, visual illusions cannot be animated. Easily disproved, like an illusitory wall you can put your hand through.
Makeup example goes here.

Fata Morgana:
Illusions now affect multiple senses at once
You can now create long glossy blonde locks, and invite people to run their fingers through it. Unless they pull up a photo taken of you earlier this evening and point out that your hair is brown and you have a buzzcut, and could not possibly have grown your hair this fast, it's "real".

Apparition:
Visual illusions can now be animated.
Here's your machine gun and your mirror.

Permanency:
Illusions don't fade at all unless its existence is disproven or the vampire undoes it.

Horrid Reality:
Seems to enchant people, exposing them to the Dreaming, where the chimera created by the discipline are real and inflict chimerical damage. Since said damage doesn't exist in the real world/Autumn World/whatever it can't kill non-changelings, just traumatise them. You can now shoot people with your imaginary machine gun.

[Vilenecromancer]

You're sitting at a table playing "Let's pretend". It's not that much of an extension from the usual detachment from reality players must put themselves in to control their usual somewhat-racist undead slaying protagonists. VTM even has the advantage in that Chimestry is a five-power line of progression with each level achieving more than the last. It's not terribly difficult to write proper rules for how this works.

The problem is this is how dnd illusion also work, and there still debating. Some DMs will straight up do unrealistic shit to prove an illusion is fake, and then act like they didn't just waste an action. Others will say it's amazing since it's very hard to realistically disprove some illusions in DnD.

The lore makes it a little easier to understand, kinda. You're basically creating illusions that can even fool yourself. In lore, the Ravnos has to experience the illusion themselves for it to work. For them to make a chair, they have to constantly watch the chair.

So at level 1, you can only affect 1 sense. Not only that, but visual illusions must be static.

Level 2, the illusion can "move" short of. The static illusion is still static, but can now change location based off your restrictions. At level 2, holding a sword or bat looks natural to others. Combine this with level 3 to add true motion and animation to your abilities. You can now light the sword ablaze!

Level 4, you can now lock in the experience. Basically no longer have to concentrate after you finish your work.

Level 5, you create an illusion so real it can hurt 1 person in particular. This illusion is experienced by everyone, but it'll only hurt one of them. This one doesn't need the previous powers to work, so you can instantly create a grenade or gun and they'll work instantly. Even if one person figures out it's fake, the one trapped in the effects won't believe them WHILE ON FIRE!

TLDR, levels 1 to 4 requires time and patience to fully set up, but level 5 is the quick draw effect of this line.

[monteparnas]

You're sitting at a table playing "Let's pretend". It's not that much of an extension from the usual detachment from reality players must put themselves in to control their usual somewhat-racist undead slaying protagonists. VTM even has the advantage in that Chimestry is a five-power line of progression with each level achieving more than the last. It's not terribly difficult to write proper rules for how this works.

The problem is the added layer. You're pretending there is an experience that is false in your fictional world. More than that, you're giving the power of fiction to a character within the fiction, with the power being meant to give this character very broad and versatile powers over the perception of others, and its weakness being a break in Suspension of Disbelief.

As both Karos and Vilenecromancer stated, this is a problem with illusion in many systems, not just WoD. At the end of the day, it boils down to two straightforward problems:

1 - It is too broad and hard to define. In my personal experience with illusion powers it is as good rule/explanation for the breadth of its effect. The more you try to specify limits, the harder it gets to let it be a free-form illusion power, and/or you get a real mouthful to explain;

2 - The "Clause of Disbelief" is a nightmarish rule. If everyone's on the same page and like illusions working, it goes smoothly. But it takes one player or the ST not agreeing that their character falls for it that everything spins out of control.

Now, for your direct questions, I'll give my standard interpretation, a baseline before discussing with the group:

1 - First Level is static in relation to a reference frame. Your body, the back seat of a car, the middle of the air inside an airplane. It is simple and devoid of complex animation because it is "minor", but don't fix too much on the "static" aspect because it won't make sense with sound. The best way to use it is to attach it to things, so you alter something's sensory properties to a degree, but a few free-standing effects can be used if the circumstances are favorable. This illusion breaks under scrutiny or complex interaction, although the reference it is attached to may help it. If you attach a fake photo to a real piece of photograph paper, touching it probably won't dispel it;

2 - Second Level is particularly better to make illusions that require more interaction, and covers most of the things you described already. And I agree that it would be better for the make-up or hair, as it doesn't run the risk of it moving strangely or breaking upon close inspection as it doesn't smell or feel right. I'd add that the make-up option would still be make-up and you would need to roll as normal to "apply" it, since you can just be a bad make-up artist and make something wonderfully ill-suited for your face. In a pinch you can try both with level 1, though, improvising for the lacking senses;

3 - Third level on makes almost everything you stated possible, including the gun. The mirror is debatable, though, because reflection isn't a sensory input you're applying to it, it is a property to reflect actual light and deliver something else's sensory input back to the observer. As others here, I'm not confident that a mirror falls within Chimerstry, but it wouldn't be a huge deal either. A fake mirror that makes up images you defined earlier could be a thing;

4 - Playing with Chimeric Reality is a thing to consider. It does make a lot of sense for the fifth level and is as official a thing as it can get in crossover rules. The benefit would be to have a more solid framework to rule its effects and the options to either bring or ignore further complications from CtD as you see fit. Depending on how you read the rules for Chimera and apply them to Chimerstry, the Ravnos may end up leaving behind some entities far more problematic than they think.