I can answer #5, about the four-notch lockring. You use a bottom bracket that only engages one notch, but pulls in a very "clean" sort of way. Much better than hammer-and-screwdriver/punch method, which I've also used in the past. The right side of the pictured Park Tool is what you'd use for a four-notch lockring:


Some of the other questions (all good ones) I have some inkling but am not sure, and it's late.