I agree, a solid pulley is a great idea. Why in the world would you want a BOV after the throttle body? Turbo cars use them to combat pressure spikes when the throttle blades are shut suddenly, which slows the compressor wheel in the turbo.
If I'm not mistaken(which I've been known to do ), a bypass valve on a positive displacement supercharger is completely differant than a BOV on a turbo or centrifical SC. BOVs vent to atmosphere, bypass valves simply bypass the intake path aroumd the supercharger. If the SC is bypassed during cruising speeds and Idle then it is not compressing air, so parisitic loss is minimized at low loads. This gives better mpg, eccentially what the SC clutch does.

If you look at all of the hot rod cars and boats over the years who have had roots type superchargers, non of them have had bypass valves.