The badge interface needs quite an overhaul. As it is, it is very hard to find out what badges you have or haven't got. If you want to find a particular badge, you need to go through each page and look at the names carefully because there doesn't seem to be any order to the badges.
There are quite a few changes that I would like to see, but the biggest one that would make the badges more accessible would be to sort the badges into categories. Side quests, monster defeating, exploring etc. Even just having a similar badge interface to Wizard would be better than what we have now.