I am well aware there are modifications to be made to CTF, but here is my version.

Chat

Make a toggle-able team chat so you don't have to always /msg each other so the enemy doesn't see it

Teams

I would advise reducing the number of teams to two, perhaps with outposts in the place of the other teams. This would also prevent the extreme imbalance in team numbers (Try winning a 1v6).

The Flag

As different as it seems to just sit on a flag to capture it. It is so easily wrecked. With the current maps, an enemy can fight you, die, and come back from his spawn to stop your capture again if it his/her own flag. My proposal instead is to actually have to take it back to your own base, and you lose it if killed. Upon the death of the flag bearer, it would return to it's rightful place. Alternatively, it could be dropped on the ground as a banner, and a teammate or enemy could pick it up.

Mobs

The spawn rates need to be drastically reduced. Have you ever tried taking the healing base at the Islands map, only to be killed by the sheer amount of zombies?

Map Construction

As I continually play this game, I find more and more flaws in the maps. Don't get me wrong, the maps look amazing, but there are several problems.
Material: Over and over again, I do/see this done to people at the mountainous map. All you do is get the good 'ole flint and steel, and burn down the enemy mines. Boom! That enemy in diamond armor can't get out.
Glass Issue: Another way to ruin the game is smelt a ton of glass, and block off a enemy spawn or the healing base. This works because glass cannot be broken due to the fact map edges are made of glass. This could be changed to using colored clay as the edges instead, perhaps with glass in front of it. There is only one way to break through these "barriers." TNT!!!
Cobwebs: I understand these are a part of the maps for the aesthetics, but try PvPing when you ran into a cobweb before getting ambushed

Enchanting

Another idea suggested was the addition of Lapis Lazuli ore to add enchanting. Personally, I believe this is a terrible idea because of the presence of bookshelves. Plus, levels carry over from previous games. So I currently have 80 Xp. Real fair for someone brand new to the game.

Rules

The game rules need to be clarified and corrected at the main warp. Two players that I know have each gotten banned for breaking the rules, when no rules have ever been formally mentioned. Yes, staff has given us insight to what is allowed and what is not, but how is a new player supposed to learn these? Not to mention the current signs at the warp are incorrect and difficult to read.

Conclusion

I look forward to feedback from the rest of the community, and will edit this as needed.