was in contravention of any rules, no matter where they come from.

As you suggest, the change of prosecution is tiny. The lack of an
insurance payout after say a gear up landing is going to be far more
painful.



And there is the rub, I would bet dollars to donuts that the insurance
company demands 100 hours whether you do instruction or not. Furthermore,
it is rather impractical NOT to offer instruction. Otherwise, how will you
ensure the capabilities of the US airmen that want to rent?

If its allowed by the FARs, and you can figure out how to do it, then go for
it. I would bet that it would be easier just to do the 100 hour inspections
in the end.