Thanks for the good word on the DVD!
Proper back-twist is essential for a round string, and it makes a difference in performance too. The bundles will share the tension better, the serving will be rounder (better release, better nock fit), etc. Lots of little differences that add up. With proper back twist, you can make a 2 bundle string just as round as a 3 bundle.
On the untangling, that is normal. Twist a few, untangle, twist a few more, untangle. Seems to be easier to do a little of each than try to twist a bunch, then untangle a bunch.
Chad