EN48, I feel that your statement
it also suggests that the approved operating envelope is so narrow that inexperienced pilots have difficuly remaining in the approved envelope, even with an instructor in the left seat.
is slightly unfair. Sufficient level of concern? Do you mean in your own abilities as a rotary wing pilot, having been a plank driver so long? Are you suggesting that instructors are having problems flying them within limits too?
The R22 was never built for aerobatics or advanced flying manuevres. It is a starter level helicopter which brought affordable(ish) relatively safe heli flying to the masses, which is exactly what Mr R wanted.
I know many inexperienced pilots, having trained a couple too, and they manage to stay within the envelope. Flying in bad weather, trying things you have no experience of, is where you'll make mistakes, not just flying as the manual states. I'd love to know why you think it's difficult to fly inside the envelope. I'd flown them for 13 years and had no problems myself, along with the majority of pilots here I bet. A bigger machine is generally always going to be more docile. Cost is always a factor. As you associated more risk to a smaller machine, you chose the bigger one. The number of R22 accidents is higher than other types, generally because there are more of them about and they are being used in a training environment and by low timers. Let's not get into another position like the late Lu Z. RIP.
They are what they are and everyone has their own comfort zone/ability.
As for doing a Robinson Factory Safety course by DVD? Bet there was a lot of mileage in that.