I don't think there are any limits on events, but only on sprites. So, there is a logical limit on sprite-generating events. I've just packed more than 16000 warp events and tested them at various corners of the level, and all work just fine. The key to to limit the use of ammo (especially crates), baddies, and other events that have pictures (sprites).

Tile graphics aren't a problem, as the game can load those dynamically as you move, but it has to keep track of every sprite graphic and state in the entire level, whether its on your screen or not.

Your level should be fine. From what it sounds like, it will be about solving puzzles than a mad baddy bash anyway.

-Nag