Livery stuff
AE has this and I think that it started out with good intentions - and anyhow we have nicer members so we won't have their problems lol.
So first I'd suggest a livery/logo section of the forum where people can request liveries and logos, as well as ask for advice on their creations. I think that this would be good for RP purposes - I think that people would really like it and it would make the forums more active.
Then I'd suggest adding a Gallery like the one they have on AE. I think it'd be a great place for designers to show off their work. Idk how possible this is in the current forum system, but if possible, I think it'd make a cool addition. This gallery could also serve as a place for people to share other photos - maybe have a planespotting section and a general photography section. I think the gallery would also boost RP participation, which I like :)