Campaign Creations

Hey, I just got WarCraft III and Frozen Throne today, but I seem to be having two difficulties with the World Editor. I've got a small bit of experience with it when my friend let me borrow his copy a year back, so I should have an idea of what I'm doing. Here's the two problems I'm having:
-I want to choose what an Aura does, but I can't find anything to control what an Aura is supposed to do apart from the variables such as how much of its effect and what units are effected.
-How do I keep the game from spawning a normal Town Hall in a map? I made a custom Town Hall for one of my maps and it keeps placing a normal Town Hall overlapping mine.

(1) Can't be done You generally can't change much of what an ability actually does, at least without fancy triggers. What did you want the aura to do?

(2) Delete or disable the "Place starting units" function in the Map Initialization trigger. Note this will prevent placing starting units for other players, so place them manually.