Mouth and Eyes as Animated Texture


I’m working on a comic-like character right now and am thinking about painting his facial expressions by hand and then applying them as uv textures.

I have two questions concerning this:
1.Is it technically advisable to work with 40 (or even much more) pretty high res textures (basics and inbetweens) stacked over each other?
2.Is keyframing the color influence the way to go?

Thanks in advance!