What you're referring to as a "gennaker" probably isn't a gennaker. It's a downwind sail (balooner) that you will enjoy sailing deep angles (150-180) with. The windspeed restriction is very conservative. Maybe that's apparent wind as opposed to actual?
I don't have a SM manual in front of me but you do need to run the sheet through a block then up to the winch.
We've built some light air reaching sails for SM's that fill in the gap not covered by the balooner.