1. I wouldn't worry about it. They sound different (ROSE-mary ANNE & ROSE MARY-anne). Go for it (:
2. Works great!
3. At first I thought it would be an old grandmother, but I've grown to see her as dainty, smart, and well-educated (like Cecily).
4. To a tee. Of course, whatever your baby looks like, I'm sure that's how you'll imagine Rosemary forever more.
5. Love Posy. Please do use it. It's so cute! (And if you're worried about the rhyming, why not do a mixed last name of your's/your maiden name & the fathers? ex.: Smith-Jones, Derring-Seals, Brooker-Colling, etc.)
:)
http://babynames.com/namelist/9697577