KJ7 : I'm going to answer you here (I read your PM). You can't remove the original gestures. One simple way to do that however is to open the "runtime.js" file and remove the line with the various gestures to only keep the one you want.
I don't really understand your second point.
For the third point, "multi-touch" can mean various things in that context. If you are talking about gesture where you lift your finger in the middle of the gesture, the original algorithm isn't going to work (the authors of the paper only made ii to work with unistroke gestures). If you mean tracing a gesture with several fingers on the screen, each finger doing a different motion, you need to check each finger as a "separate gesture", and validate the whole if and only if all the separated gestures are validated.