How do you synchronize the start of a player to a division bar 0, 1/8 , 1/4, 1/2 of another looper? What is masterMsElapsedSinceLastBeatfor?

Syncing happens with masterMsElapsedSinceLastBeat. That's the value the player is synchronizing to, and you need to manipulate that in order to start at any point you'd like to.