what needs to be done to sharpen a prop? how is it possible to balence a prop without a prop ballencer?

It's almost impossible to balance a prop without some type of balancer, weather it's one you've purchased or homemade. A home made one is not that hard to make, a couple of single edge razor blades and a shaft and a couple of blocks of wood and your in business. If you look a little deeper in RCU you could find information on how to do both. Good luck.