Will Windows 7 want two license keys if I go Bootcamp + Parallels?
You should be able to use a single license for both Boot Camp and Parallels 6. When I set up my Mac this way, I just had to activate it twice, first booting directly into Windows 7, and again after setting up Parallels to use the Boot Camp partition. 

I think I may have actually had to activate it once again the next time I booted directly in to Windows 7, but certainly after a few activations, the activations in both environments finally stuck.