So.... theoretically, I'd probably install such a mod for one run, at least. But it would need to be really good. All the cutscenes adjusted, for one thing. Maybe tweaks to the voice, as you said. There would even need to be work with tags and changed dialogue lines. Just swapping one model for another wouldn't cut it for me.
Yeah he would have to levitate or something where there is touching involved. In other places, conviniently placed chairs, rocks, and pillars might do the trick.