I was shocked when I was told that if I had an R22 license, I could fly any machine if I could convince the owner would throw [me] the keys. I could also fly over a built up area in a single engined machine and then do all of this all at night - all with no extra qualifications or training!!
Is that the case? I'd have thought that you were still under the restrictions of your UK license unless you get an FAA piggyback? (Not sure why but I thought you had a UK license, now I'm not so sure?)
I.e. night only if you have a night rating, R44 only if you have that type rating etc?