RE: Tiger Stick 40 Rolling Too Slow
Some servos, espeically inexpensive sport sevos don't always deal with being sent to much beyond 100% throw. So just using EPA and DR to push the servo past 100% won't always work, and will sometimes give funky performance at the end points. You're better off adjusting the linkages to get more throw. And yes, you sometimes have to adjust the pushrod length to re-center the surface afterwards. It's no big deal.
Personally, I use a lot of expo on some of my planes, but you should probibly start with smaller amounts of expo and smaller throws and see if you like it. Some people like expo, some people don't. (I've even seen some guys who dial in a little reverse expo to make the plane more responsive around neutral and softer at the extremes, but that's not common. I've flown that way just to see what it's like. It's interesting, but I didn't like it).