I did a bit of a ctrl+f search in the archived topics, so I hope I didn't miss either of these things if they were already discussed.
Consider this a dual suggestion, but they both pertain to the same section of the forums, and I didn't think it'd be cool to make two threads.
1. Not a totally big deal, but sites like DayZRP.com allow you to change the entire background of your profile page to an image of your choice. I understand this results in larger file size uploads, but perhaps you guys could include this for veteran/donating members of the community? You can, of course, inhibit larger file sizes as you've done with avatars/cover photos to prevent over-sized files from being uploaded.
2. Profile music, to show off a bit of personality on your profile to whoever is viewing it. I know there are plugins out there that allow this and folks like me who like to doll up their forum presence would appreciate it heavily.