NPH has a very simple voice, and I don't really think it would work for Georges/George.
About Audra being too soprano-ey, Audra has chest belt on her that is to die for. She also has a VERY strong mix. Listen to the 94 Carousel! I've said it before, but she's VERY polished, and the rest of the cast would need to sound a bit prettier so she doesn't sound she doesn't belong. Her voice is perfection. The London revival has a bit of a rougher sound. Which is in no way bad.
Would love to see Ruthie. I don't think she looks too old, I don't think. I think this role is MADE for her, type wise.
Sherie, Julia, Benanti, not so much. I just can't really see it, at all.
Julia's a bit too loud for me. TOO big of a belt.
Personally, I think I have too much bloom.