re: boost setting, i cannot explain it well but Code 1 and Code 3 (Aux2) sets the boost, while Code 2 is turbo. i just did a trial and error, good thing there's SSL so i don't have to pit to change settings.
re: Throttle feel, i think 0 setting is comparable to 100% punch in other ESCs, and the more throttle feel you dial in, the less punch you have on the Vortex that's why it feels smoother.