Yes, yes, yes!!! I've loved
Cosette for so long! Ever since
Les Mis... But any combo I've ever thought of has had
Cosette as a middle name. I agree about Cozy being a bit obnoxious, though it'd be pretty cute for a small child :) If you were to use
Cosette as a first name, I'd have the middle name begin with a vowel. The combo at the top of my mind right now is
Cosette Amelia.