> #3 is super annoying - but also why can't I bulk edit associations?

You can.

Right Click -> Open With -> Other... (Always open with checkbox)

is for setting a particular association for the particular file you right-clicked (maybe you always want this file to open in Sublime, but this other one with the same extension in TextEdit, for some reason, etc).

command-I to open the Get Info pane -> expand Open With block -> use dropdown labelled "Use this application to open all documents like this one" -> click Change All... button

is the bulk edit flow