Trigger crates that can turn off triggers and regenerate properly

Yes! Needed badly.

Server-only start positions, where only the person hosting the game may spawn

Meh. It can be done easily. But an auto option would be nice..

Instant death event (as in a hurt event that does 5 damage)

Hehe...Evil..

Events that "tint" the level a certain way, kind of like how the smoking caterpillar (sp?) does. Used instead of lighting.

Maaaybe..

True random trigger zones (unlike the kind where you use the "switch" parameter)

Again, possible, but an automatic would be much easier.

I think that the most important would be trigger crates that turn off and that they can both regenerate. Oh, and for triggers in general, more of them. 31 for crates just ain't gonna cut it.