Good point Ghetto. Yes they could easily enable / disbale friendly fire in the playlists. But I think that is only half the problem. Most hardcore playlists and the really competative guys, dont want that friendly fire stuff. Griffball is a good example I guess. If friendly fire were turned off, you'd have people boosting eahother to the goal all over the place, making it that much harder to actually play a good solid match. Same would go for CTF. In most cases it seems, due to the way the netcode is written, and how the new Havok Collision detection works, it makes it harder for the game to properly report which damage to apply and when to a specific target.
For example, say you were charging a guy at his base with the bomb. Your about to die from some DMR fire, and your buddy throws a grenade. Said grenade detonates directly under you feet. At the same time or possibly bout 32mls later, a DMR shot hits your head. Now becuae of latency and and damage reporting timings, the dmr bullet will be nulled, since the game is currently in that 32mls to 70 mls range, negating and sorting that friendly nade and it's damage.
Like Absolute Dog said, the code base for MegaloScript alone is huge. Too huge even for me to grasp 25% of what it is capable of, and to what extent he side engine contains. it will never be as simple as just making a few syntax changes. One small change that seems okie dokie, could well end up breaking the whole combat system.