I love [name_f]Caroline[/name_f]!
For a while, I would have said [name_f]Catherine[/name_f] / [name_f]Katherine[/name_f], but now I’m definitely more of a fan of [name_f]Caroline[/name_f]. If you love the nicknames, then that’s a big bonus.
If you don’t like [name_f]Kate[/name_f] or [name_f]Cathy[/name_f], I’d reccommend shying away from [name_f]Catherine[/name_f].
I definitely don’t think [name_f]Caroline[/name_f] feels ditzy, I picture someone quite professional. I think it feels beautiful and elegant. I used to feel the same way about [name_f]Catherine[/name_f], but I just feel that while it looks fairly pretty, the sound is very much less so. If it’s anything, I prefer [name_f]Katherine[/name_f] with a K.
I would say go with [name_f]Caroline[/name_f], but at the end of the day it’s up to you!
Also, I haven’t looked at historical usage, but I’d say [name_f]Caroline[/name_f] feels timeless, or at least classic. It doesn’t feel dated to me or tied to a particular period.