In Texas you can cut within the tackle box. No player who starts outside the end man on the line of scrimmage may come back toward the ball and cut. I guess the best way to describe what I'm calling "reach and roll" is essentially flopping in front of the end and rolling.
In my experience it doesn't matter what the DE runs, he can't play off a rolling defender to use that speed. Also, if they choose to use that speed to jump outside, then the dive off of it will gash them. In fact, the dive is hands down the most successful play of the series. We put our best back at fullback, not one of of the sweepers. The fullback (what he's called in our scheme anyway) has 7-8 opoportunities to get the ball, whereas the sweeper has only one.
I have a video playbook on DVD that shows our fly series (we call it "jet", but I've learned here that isn't the most accurate description), with slow motion to show the blocking. Free to anyone willing to trade good ideas back this way.