I recently came back to the game after four years or so along with some friends, for various reasons our characters were all on different servers so we had to make new ones to run as a group (couldn't afford a character migration at the time, plus preferred world bonus does not apply to old characters) but this left the lot of us with characters we're just not using.
We'd rather not just delete them, but we aren't really going to be playing them, and we'd like to not lose out on all the work already put in. So I was thinking, what if they offered a service to move all exp, and currency from your other characters into one (probably on a character by character basis) for a fee. Items would be...a bit problematic...with space concerns and all. Quest progression could be moved over though...

Unrelated to the first suggestion...how about a crafting bag? With one character being able to do it all, the inventory is significantly small to carry all kinds of gear on top of crafting materials.