What's the best way to have different people use the same ION Xe 20 console? I am at a school and I don't want the kids to change the basic settings.

No there isn't. All those settings however will be stored in the showfile. So if you just load one of your showfiles afterwards everything will be the way you had it.

How bout shift escape? Although once anyone knows that then it does not protect. Then reopening fixes.

I still wish they would put log ins on desks that can limit the abilities of users. Yes I know some venues/people hate that for a variety of right reasons but it would not have to be activated if not needed. Just like any standard computer.

You can create a magic sheet that has buttons on it for the more day to day usage that it will get in a school setting and in 2.8 you can set it so the magic sheet is full screen and cant be got out of in an obvious way.  Its a kind of kiosk mode for operation by untrained (almost) users.