I love Catherine(I actually prefer
Katherine but
Catherine is lovely as well.)
There are 3 Cáitríonas in my husband's family - they go by
Kate, Cína(Keena) and
Kitty.
1. Nicknames -
Kit,
Kitty, Cate/Kate,
Katya,
Katie, Cat,
Rina,
Trina, Cath,
Cathy, Katisha,
Katinka ,
Kay, Pussy(not recommended). I love
Kate and
Kitty.
2. Same issues someone has who goes by a nn - having to explain their full name/real name every so often. It would only be an issue in official circs though surely. Having said that my mother has always gone by her middle name and she dislikes the name and finds it a nuisance.
I like
Catherine Amelia. But really - use
Catherine - it's a great name.