They should just make a custom level editor kind of like an ole. Having a level made using the offline editor allows npc scripts to be added, which can severly cause problems. Inspecting levels would take forever, and with thousands of players it wouldn't be easy. Yes its done for graphics, but you only need to take a glimpse at it. With levels you need to not only look at the level, but every single npc script. Also, if an administrator misses a npc script, the result could be disastorous, such as creating a massive ban wave or giving everyone on the server gralats.

So just make a special ole for houses :3