There's nothing wrong with taking inspiration from other games, all art takes inspiration from those that came before it. That's how it works actually :p Malkavian characters have their Cobweb which isn't prophetic per se, they just use their combined experience and non-arcane insight to predict events and have uncanny understanding of a given situation. This comes subconsciously though and most of the time doesn't make sense (to them). VTMB is one of my favorite games and, while unfinished, is one of the best RPGs to date. I don't know whether the Source can drive you mad. I don't know much about it to be honest, it was mostly healing magic in DivDiv, but I don't remember what they said about it in the other Divinity games. If it's like the Force, where it can be used as plot insulation for anything, then go ahead ;d If there's some specific description of what the Source is and does then it won't work.
I think we need a better understanding of what talents are supposed to be. They are so different from one another that I don't see what the initial idea has been. Pet Pal is a nice example, it's ridiculously different than everything else (in a good way). Are they supposed to customize your character? If so, then in what way? Are they supposed to increase your power? All those +damage talents seem to suggest this. Are they for convenience sake? I really could go on. They are so over the place that I can't find or follow the initial logic.
