who makes the paddle? I think a 6 paddle would be way to much for a stock motor. If possible, you may want to look at a 4 paddle if they make em. If not, you can have Skat Trak make you a custom tire.
As for the whip, mount it above the tire. Whips have a tendency to get cought in the tire and get shredded. I made a custom mount to my exhaust pipe and mounted it there. It was one of the best things I ever did to my bike.
I use a Stiffi quick release mount for ease of install/disassemble and it makes fixing a broken flag REALLY easy.