Yes, they are over the top, but if you love them you should use them anyway. I went to school with
Aristoteles and
Ceridwen and you really do get used to it! Haha I disliked Caillou as well!
Rosie makes me think of a sweet little girl I once knew and that association is stronger so I still love it.
Kleio is actually a full name and
Clio,
Cleo can be seen as spelling variants but I can understand that they seem nickname-y to most people, I first thought they were nicknames as well.
I don't think
Serafina is too close to
Saoirse. Yeah the association with Flockhart is unfortunate. I suggested
Callista (she spells it
Calista) so the association wouldn't be too strong but I guess it didn't work :P
Callisto is a name I liked for a long time but it might be a bit too much.
I think
Talia (which is also a legit name with a different background) might help with the pronunciation issues. I think most people would pronounce it TAH-lee-ah. Of course I don't know whether that's the pronunciation you like.
Anyway, good luck and feel free to post again, I think we'll all be glad to help. Finding the perfect name can be really difficult.