I wish alts could share a house with the main character and being able to mail things to each other would be nice too. I wanted so much to have a shared garrison in WoW, I hated that each alt had to manage their own.
It's basically guaranteed I'm going to have alts because I like playing different races (and redoing content doesn't bother me at all). Fantasias just won't work. I've never raced changed in WoW either except one time I faction swapped and ended up regretting it later because I wished I'd kept the original character.