Only change I'd make given your timing is to be at Leverick Friday night for the BBQ. If you do two nights, you could do Thu/Fri or Fri/Sat. Personally, we like the Thu/Fri and rent a car, go out to dinner Thu night on island (Coco maya usually) and then tour a bit Friday before being back for the BBQ.

Can't speak directly about Orion - but I will say if it is a typical dinghy setup 11-12' with 10hp engine, then you will either go VERY slowly with 10 or need to make two trips.