RE: CARBON FIBER PROPELLERS
Pylon racers use carbon fiber props, injection molded. These props turn in excess of 23,000 RPM but are very small diameter (approximately 8") compared to what you are using, they are sometimes shortened. I have recently seen one that had a small nick near the end repaired with CA and micro-balloons, although I am sure no one would endorse such a repair. Personally I would not hesitate to shorten a CF prop from what I have seen if needed.
wkevinm