(Question: would it be possible to add markers for all of the Shrines of Gaps to the worldmap?)
Not a bad idea. I'm sure it could be done. Time for SCIENCE!
EDIT- aaaand done. I've added markers to the Livefeed map for our 23 currently established warp points scattered all across the main world. There was a long list of icons to choose from, but I picked "ruby" since it was easy to see from any zoom level. The name displayed is the warp destination name, but you already knew that.

Hopefully, this will give people a better idea on which areas are claimed by others.
Now for the other recently mentioned subjects:
Clay -> Brick recipe - Honestly, I don't really care for this idea. Sure, Brick is one of the most resource demanding blocks there is, but it is legally obtainable without our meddling. We try to provide recipes for items that aren't obtainable by normal means. Sorry, you're stuck with smeltin' the clay balls just like the rest of us. :V
Player-generated Adventure Worlds- This is a good idea, but methinks that not too many people would partake in the endeavor. I'm not sure how difficult it is to manipulate the settings in the TerrainControl files.. Stuffman can explain things better. If anything, this would call for players to install TerrainControl on their home machine so that they could test their creations. That way, we don't get flooded with asinine requests. I'm not that knowledgeable about this mod, so we can still talk about this.
BSOD MAZE- Oh, how I am reminded of DDR's maze event from waaaay back when. He had a modest turnout since there were two prizes up for grabs. His maze was 3 sprawling layers, each layer was twice as large as the previous one. Not only that, the deeper layers were more difficult. (Final layer was complete darkness :V) It took him quite a while to build the maze on a separate world, not to mention all of the redstone required for his failsafe switches.
Sounds fun, although you might want to offer up some prizes to really increase player interest.