Yep, I have done that as well; very funny to watch.

The AI guys are actually capable of opening any door they want, locked or not, so you can sometimes actually get to areas that you are not supposed to be able to at the time by hurting a guy and letting him run to the door.

As for spawning stuff, you have not seen anything yet; for example, in the Paul Denton area, try spreading either lab flasks, basketballs, or computer terminals (computerpersonals) all over the floor, call the MIBs in and then watch the fun.

Or, if you want to play around with that bathroom door I mentioned earlier, stand in front of him and throw a scramble grenade (nanovirusgrenade) at the opposite wall, and he will run into the bathroom and then start walking back to his seat. (at which point you can obstruct his path with the door and watch the fun)