Character creator

I’m building a character editor for my project. I wouldn’t say I’m stuck, but I’d like to have an advice from someone who knows better than me, so I avoid unnecessary mistakes.
I use Blender to create models I need. I have most of what I need already. What I want is a Dragon Age: Inquisiotion style editor:
Practically I want to be able to modify face shape, eyes, ears, mouth, character height, character weight. Additionally I need facial expressions for talking and various emotions.
I’m aware that I can use morph targets and a rig. I plan to use skeletal animation for talking and facial expressions (which don’t have to be very extensive), and morph targets for character creator. However I’m not sure if it’s possible to use both at the same time without problems like having a face which wouldn’t work well enough with a skeleton, or ruining other animations by changing height of the character.

So, what is the best and least time consuming way to do that? To follow my initial plan, or better use another way?
I assume that it’s possible export both skeleton and morph targets (shape keys) from Blender ^^. Btw, is it possible to export shape keys controlled by bones to unreal engine?