[Mad Max]

Get a throttle lock. There are a few companies that make them. They mount in btween the throttle grip and the right housing on the Clip-on.

A fast idle lever is probably not going to give you enough power to do "tricks" or act as a cruise control

 

[Mad Max]

I don't have one myself, so i can't point you in the direction of which one to get but here is a little picture of the instructions from a NEP throttle lock.

More info