In all of my flying I've never been in turbulence that's really required seat belt
You should have been over the Rockies last week then. Even the 5-point in the flight deck wasn’t keeping my plus size butt where it should have been.
In all fairness, while this sounds like an interesting idea, amusement park ride is about as accurate as this sounds. This would have to be a private endeavour, as no airline would intentionally subject themselves to the litigation that would surely come from an injury. Of course, organizations provide flight simulators for the general public, so who knows...a small, niche market for sure.
As far as “exit certifications” go, that just won’t happen. Off the top of my head, I see training and personal insurance sad being the first two limitations. Training would be the easy part, but insurance...No airline would cover a passenger should they make a mistake during an emergency, so you’d need a form of personal liability insurance. I can hear the ambulance chaser two houses down licking his lips at the thought...
With all that said, if you just want the experience of pulling on plastic things to put over your mouth, being yelled and screamed at, thrown about like a rag doll, then tossed out the front door I would suggest Regulation in Islington might be a better place to ask these questions
(I kid of course).