RE: Back tension question
First thing I'd recommend is to make a loop that you can use that matches your draw length instead of trying to learn this thing on a bow. Use the loop to figure it out and then move to the bow.
Without seeing you in person it's very difficult to give you more advice. I'd recommend getting a copy of "Core Archery" by Larry Wise, it's a great read and will help get you pointed in the right direction.