Just use 1/1 event novice, and that solves all guild chat/party chat problem.
Your remaining problem is to fight against alt-tabbing.
-Spawning monster isn't a good idea because answering requires you to stop moving and type. You die either way from this perspective. You got room for people to pretend they are answering, "died" to the monster while answering, and that's plenty of time to alt tab during this excuse period.
-with or without audience, the "MSN/Vent cheat" applies. Just that the one being questioned will be the one to ask on MSN/Vent and then everyone else replies. Vent is the ugliest one since it's far faster than MSN. You just talk and there's response.
Speed is 'generally' the best solution to fight alt-tabbing. Now that I think about it, Weakest Link is probably the most "RO-friendly" game show possible since speed is now a concern. Feel free to alt tab, but you're wasting time for a higher zeny score.
If we want to keep it on Millionaire type of thing, part of it will depend on how the question is worded so that it's not just simple trivia, but things you "can't look up for." Riddles or facts outside of heRO wiki/databases maybe? Problem is that this greatly limits the scoop of potential questions. Overly difficult cuts the fun.
Keep thinking though

it's these repetitive process of balancing between integrity of the rule and convenience/fun to the players that new events are made, and old events get better.