Archer,
all this is good stuff, but you are in danger of sitting the PPL helicopter theory course before even starting! If you are in a Robinson, the governor will maintain engine RPM and thus Rotor RPM automatically for you. Because Robinson's wisely derated the Lycoming engine, you will only get a small droop of RPM when you pull in power. Infact you will generally red line the Manifold Pressure before you get a low rrpm horn.
I personally think that you cannot be taught how to hover - it is a skill that can only be learnt by experience and it is some experience! Best tip I can give is rest your arm on your knee and hold the stick with your finger tips. Hold it in your fist and you will have the cyclic grip inprinted on your palm for a week.
Tail rotor roll is due to the tail rotor not acting in the same plane as the rotor head. That is why you see larger helicopters with the tail rotor on top of the tail fin.
Oh ****** you've got me doing it now!
Chill out, go out there and have a ball. But remember to leave all your fixed wing skills behind and watch out for the pedals. They are feather light in an R22 and I've had more trouble teaching Archer drivers than complete novices - the pedals in an Archer must be real heavy.