question 1 : Yes. Use the same topology for all heads, treat each new face as a blendshape and simply apply that to the base model - the expression / phoneme blendshapes will ride on top of that. The faces do need to be fairly similar in shape to prevent bad stuff happening but in sensible use cases it's very effective.…
We're working on an RPG with 90+ characters, so we can't start from scratch with all the blendshape sculpting for each character. For now we're only concerned with male characters, which all share the same base mesh. Right now, all the different characters are set up as blendshapes of one rigged "neutral" base mesh. The…