This is very good. It’s far beyond my VST manipulation capabilities right now, so I can only really comment as a listener. Nice use of dynamics in the beginning. I didn’t really think about the artificial balance of the solo violin until Mobius mentioned it. I certainly see what he’s talking about, but I also see your point about considering the purpose. If it sounds good (and it does), it’s really more a matter of approach and intention rather than a matter of right or wrong. Thankfully, once you pass a certain competence level, most music is that way. That’s part of what makes it an artform.
As far as the choir goes, I think… given where it sits in the mix (which is pretty far back) it sounds pretty decent. There are things about it that don’t sound real, and those things would become more obvious if you were to bring the choir more forward in the mix and try to replicate the kind of dynamics and expression a choir is capable of, but since you’re sort of hiding it behind everything else, it actually sounds damn good the way it is. It certainly doesn’t call attention to itself, and that’s the whole point.
Anyway, again, what you’re doing here is beyond my abilities, so … take what you will from my thoughts. It sounds very good, and could easily be thrown into an action sequence of a video game and I wouldn’t think twice about it.