Woodpile:

First thing I would check is the balance of the prop. If it vibrates excessively at idle, you may have a heavy blade on one side. Get the Top Flight prop balancer, or at least the finger tip model. Clamping the engine to the bench shouldn't matter - if the prop and the spinner are in balance it should smooth. As for glass vs. wood, the glass prop will flex forward somewhat at top speed, but that is part of the flexibility and helps it to not break on a tough landing. Wood props are a little safer if you are hand flipping to start, but you will need to keep several in your field box because they break rather easily. As far as max RPMs, a tach would be best to verify which prop is turning the fastest. Someone at your club should have one you can borrow. Personal preference - I like the APC sport props.