1) do you run parallels-windows through Boot Camp, or another drive, or both?
both - I have to
2) if both, is parallels-windows faster on a non-Boot Camp drive? or about the same?
Boot Camp is faster one virtualization layer is off - virtual hdd
3) if running on more than one drive, I'm assuming this requires a windows installation in each place, and a virus protection install in each place, yes?
Do you want several Windows installation?, if true - yes