Well, I would definately recommend more PM folder space. Enlarge it for normal users and double that for mods. I try to keep as many as possible archived in there but it gets clogged.
As for stores, pets, things to buy or arcades, I think anything you get points to 'get' in the forums, you should just get. If I am going to spend time in a game gathering funds, it'll be in GK.
It would be cool if there was a dropdown list in the profile for most often played server, that would allow you to show the your online time or in game profile stats for that server to the left of the post, instead of the funky stats we had before. I bet likely not practical, but I think it would be interesting.