Re: Prop ?
Not sure what you want. You said it gets on plane at 15mph with 1-2 people and with 3 people at 11mph. assuming you have those numbers switched you are getting on plane. if you have too much weight forward it will affect getting up and as ststes, the angle of the moter has an effect as well. Before I messed with the prop I would trim the motor differently and see what happens.
When you are up to your butt in alligators, it is hard to remember your intent was to drain the swamp. Stay focused!