You really should add a minigames lobby, there are so many minigames and no lobby for them. I suggest you to make it so whenever you click the emerald (minigames) in the navigator at the main lobby, it will teleport you to a big lobby showing all information about each and every minigame, with portal or signs (or both) teleporting to it. It will be very useful and helpful for people who wants to get some information about a certain minigame. Another idea, I suggest you to make different minigame lobbies (where you wait till the game starts & picking team) for each minigame. It will make the each minigame to be different in its look. It will make some minigames to be more interesting, not just have the same lobby for all the minigames.
Support and no support. Although it is a good idea. It would just add a crap ton of work for builders to build a bunch of new lobbies.
Not really, there are many ways to get builds without using official build team; they can open map submission requirement, use prebuild maps and more