I like Vassy's 4th idea. I would also think a user rating and ranking system would be good. The rating system is where everyone on the site can rate a user once. If they change their mind they can back that down. It is summed up so the users have a rating out of 100. The rank system: users join with a rank of 1 and work upto 10. 10 is for really good mappers and 1 is for new people. The more maps they submit that get good scores, the quicker they will rise up the ranks. Although, the ranks cant go up too quickly otherwise people will be on rank 10 in weeks. They have to take a test at the end of the rank based on tutorials for their rank. On the other hand, having less ranks will be easier. So maybe 6 ranks. First 2 are beginner and 2nd 2 are intermediate and so on.
The map vault should be split like vassy said, but no model vault cos this is a mapping site. Then, there could be vault moderators who review each map before it is put up publicly. The official score for the map is from the moderator's review. This could mean that maps take longer to be put up, but it would filter out worthless maps. We would need alot of vault mods as it would be hard work tho. It would be better if our map vault was like snark pits. Not a similer system, but the fact that only good maps are one there (with a few exceptions). But anyway, there could be a beginners vault, and a advanced vault for each category so people with different ranks go into different vaults so they dont get mixed up with advanced maps. Also, users CANNOT vote their own maps, and only registered users can vote, and once at that.
The forums, well, the mods need to be stricter. And maybe a feature so users can edit/delete their own posts. And maybe for the mapping problems forum, a solved/unsolved icon like the snarkpit has. This would stop people bringing up old questions that are now defunc. Maybe a limited posts per minute so users have to wait 30 secs between each post to prevent major spamming.
Most of this was in my email so if andy or atom doesnt get my email, they will read this.