What openings are usually good for a simul? I'm assuming that it's an all-comers simul, so there could be strong players mixed in. Does the answer change if the strength of the opponents is known ahead of time?
I've always heard that person giving a simul should strive for quiet positions, where they can use their superior understanding and not have to calculate much, and his opponents should strive for the opposite: complex, tactical positions. Even GMs can miscalculate while giving a simul, since they have so little time per move, and so many boards to worry about. This makes sense to me, and I think this holds regardless whether strength of participants is known in advance.
Having said that, there are some crazy Morphy and Alekhine tactical wins in simuls, even blindfold simuls.