I only scanned through your post as I really need to rush and get ready to go out in a mo lol but, from what I've read....
Its your baby, your life, your the one carrying the baby, therefore its your decision whose last name the baby has. Normally I'm guessing that if you and this guy aren't married, then the baby would take your name.
I'm expecting my little girl in 7 weeks and she's taking my sir name partly because me and her father are over now and he is having little to do with her, and his name isn't going on the certificate, but if we were together then his name would go on the certificate as the father but she'd still take my sir name unless we were married.
hope that helped...x