one day I was inspired of this amazing tapping, because of m0nk, few months later I started to learn finger roll. It was long time ago, when I didn't know what league is. I lost my control skill just for learn fr. I guess I could be much better now without fr, but now... I can't stop and it's just my style.
I can get fast tap, 12 taps per 1 sec is enough for worms, but I don't use it much, I get fast tap while shadow etc, which you will get easy too after longer time of playing this game, even without fr.
If you wanna get some advices from me, so as someone wrote before at start you just need to accustom your fingers to finger roll, it means you do it slow and clear. I started to do in on wxw maps, but it wasn't about touching the walls, just get a control with my fingers. Then I started to press space as fast as I could in shoppas, came back to wxw with walls, and to this day I play rope race. Just train it, I used to train it for long hours offline

here is my video, you can check my fingers:
http://www.youtube.com/watch?v=TCLJ6QZUTpUand don't worry, if someone can, you can do it too, if you got at least 2 fingers on your left hand!