You guys seem like you'd know how to remove projectiles from the map. I want them removed in a certain area so people can't treb certain objects. Any idea how to do this?

Use Trigger Studio and make a trigger like this:

Starts: ON
Looping: YES
Effect: Remove Objects: Proj, Trebuchet*

*I don't know if this is the right one, because I haven't got time to check right now. You could try to locate the projectile in the .dat and then try to find it in the data.xml in TS folder to locate it in the list in TS.

Excellent. Thanks once again Basse. This method works for the God's sling in addition to the treb.