A lot of the game feels like it was designed with the idea that people would mostly only play one character honestly.

You can't even send mail to your other characters without using a glitch to add yourself as a friend, a glitch they may have fixed by now.

IMO they should update both the housing and mail systems to work better with multiple characters. Let you send mail not just to friends but also your alts on the same server. Give your characters housing access on the same server too if on the same service account/server.