I do until around the 1870's, than there are so many units that it becomes such a hassle.
I occasionally name them after male genitalia... should I feel bad?
yes, i name them after which purpose they have. if I am to invade some country i name them for instance "Greek Invading Army" etc. It makes things more organized
Can you actually rename specific ships?
It's more of a way of looking at unit list and knowing WHERE my units are than flavor.