Re: Appearance, I think using Appearance as a cap on *Attribute* dice in situations where Appearance matters strongly is a good play. Possibly Appearance as a total cap in purely first casual impressions.

Re: Firearms- Using Wits does make for a chronicle where Torador/Brujah/Anyone with Celerity are going to strongly favor melee and thrown weapons over guns. Might make a good flavor change, but definitely shifts the feel of your setting.