Hey there!
Digging the ideas! The posture one would be a bit tough to do as that would require going in and changing code and animations to make sure that everything lines up with different personalities, but it would still be pretty cool! As for the eyes, I 100% that we should get some more options for eyes. While that may not be high on the list to get updated, it still would allow for quite a bit more creativity when making characters.
Keep those ideas coming!