Sin 2 definitely seems geared towards Vicissitude which is "weird" enough in itself to me because it seems to exclude from the path anyone (including Tzimisce) who doesn't practice one specific disciplin. Except maybe if that person seeks out the help of another Vampire who actually is a fleshcrafter.
As for Sin 3 and a more metaphysical take on Sin 2 one could try to go with.... Well I COULD imagine something but its also very specific in a different way.
There is another RPG I'm into, Eclipse Phase, which is a SciFi RPG with a Transhuman background where you can digitize and upload your Ego. There are people called psychosurgeons who can modify an uploaded Ego to change it, changing the person in the process. You don't usually perform psychosurgery on yourself though that might be possible in one way or another.
ANYWAYS, what I'm trying to say is: I COULD see a Dracul/OCT try something similar with their skills in Auspex and Dominate. That would also be quite specific of course since it would probably require rather high levels in both disciplins as well as in the corresponding skills. For example, you probably need at least Auspex 2 and relatively high levels of the corresponding attribute+skill pair to be able to make a meaningfull analysis of someones psych that way.
It's not as if I've thought this all the way through of course, just a thought that crossed my mind.