My much older rolleiflex automat is the same, the speed dial/stops were the same on all the Rolleiflex, yes, the dot near the 22 is 16 and no you can't set speeds in between, on many german cameras of the era click stops for the shutter speeds were not there, and the line in the window is the set line, I suppose yes, you could approx 1/2 stop settings, by using the halfway setting, as far as the strap goes I can't help you, I don't use the original strap, prefering a wide strap for comfort Hope you get a lot of pleasure bout bof this rolls royce of cameras.
Richard