1, avoid the open framed colts or brass frames. Not favourite for target shooting.
2, Excellent choice, as with any gun the price reflects how much better it should be. Stainless costs more but will stay good for longer. Most prefer a .44 but I have seen better accuracy with a .36, and bearing in mind we are target shooting this should be the logical choice. I guess some prefer the bigger bang/greater grin factor.
3, Many turn their noses up at the alternatives because they insist on the spirit of the original. I'm a target shooter and choose the easy life so 777 for me.
4, You hit the nail on the head as to why use alternatives except price tends to be higher especiailly 777 at around £35 a pot but it lasts ages so not really something to bother about.
5, We all have our own cleanig regimes, one at my club using pyro just brushes and sprays with WD40, I have a scrub out with boiling water then spray but put extra effort into the nipple threads.
6, AirgunBBS has some helpfull chaps in their muzzle loader section
“If a cricketer, for instance, suddenly decided to go into a school and batter a lot of people to death with a cricket bat, which he could do very easily, I mean, are you going to ban cricket bats?” :- Prince Philip said after Dunblane