This, it seems, will all be resolved by new regulations/clarifications rushed through immediately following the first death/serious injury accident on a Wingly flight.
I would expect an FAA type set of rules.
Personally I own and operate a US registered Archer II, it is maintained to public standards - you want you can rent it, fly it yourself after a check out with a CFI - just want to zip around the island or to another island and but are not a pilot - I will rent you the airplane, all you need to do is find a commercial pilot who will fly you in "your airplane" - there are several here who will fly you for free, they get the hours towards their ATPL count. Legit by FAA standards, no holding out by the commercial pilot and the person flying is dealing with someone 'properly' trained AND EXPERIENCED.
I think this whole thing is dodgy, if they had a requirement to need public cat airplanes, minimum hours, IR or IMC etc. I could see, maybe, something that makes it legit but it just seems all rather "off" that a sixty hour PPL can be offering something like this. Also, I am not convinced that any of the mix of insurances mixed up in this would ever pay claims - time will tell.
Thanks to all who have participated in the debate following my original post on this, I think, important subject.