Guess we will have to disagree on this one. GM of course has the final authority. But having a 2nd adult to assist can be a huge time saver. If the GM has to choose between a kid going "I have to pee, where's the bathroom?" and leaving the rest of the kids unattended, what do you suggest?
Letting the 8-12 year go to the bathroom by themselves. They do it every day. If the kids are so young that they cannot go potty by themselves, they are not ready to be playing D&D outside of a family situation.
We definitely disagree on this one, but I think every teacher and coach will agree with me: the last thing you need or want is a parent becoming the de facto authority figure instead of you. The kids won't mind you at all if you do that.
Or one of the kids says "I want a hamburger NOW!" and the nearest burger place is 5 doors down from the FLGS? I have been in games where the GM was also playing primary parent and saw an 8 hour game slot turn into 2 hours net of gaming. Maybe you are a far better kid wrangler then most folks.
Probably, considering that I do it professionally, but my answer to that specific situation is "no." But I also would NEVER schedule an eight hour game with 8-12 year olds. Why would you do that? My God.
If doing more than an hour, you need scheduled breaks where they can get up, move their bodies, eat, drink, pee, chat, whatever. Even with breaks, I would not go over four hours total of D&D, especially if these aren't your own kids.
And as far as establishing what the parents are expecting for their money, part of that is just how much authority the parents are ceding to the GM during the run of the game. This GM is basically entering into a Service for Hire contract and had better have everything clear before accepting the job. As a teacher, a lot of that is defined for you in your employment contract and local school policies and procedures.
Yes, but set it up in advance and don't negotiate. You're taking care of children. You have significant ethical and legal responsibility. This is not a thing you can half-ass, make exceptions on, etc. Parents are
always trying to make exceptions.
Where I teach, and I suspect in most places, teacher responsibilities are actually set out by law; here in BC they are part of the School Act. Local districts and independent schools build on that and offer clarification. We also have to have regular criminal record checks, and our responsibilities to some extent extend beyond the school day. It's a whole thing.
Running a D&D Club at the local FLGS is obviously a different order of magnitude. However, you still are taking on responsibility and need to be prepared for what that entails, same as if you are coaching a team or running Scouts, etc. And that FLGS really should be doing criminal record checks or they are both irresponsible and incredibly liable, and I wouldn't let my child attend unless I knew the DM personally and felt confident vouching for them.