Its funny you say that because my boat does not reverse like I thought it would but my buddys boat with the same bracket will go reverse damn near as fast as forward. I figured id was because of the size of the transom I have.One thing to bear in mind about these units is that they work great going forward but not so well in reverse.
shallow or well below water line doesnt show noticable difference. As for props, on my motor again it wasnt significant and im as low of a pitch as i can get for the motor. May be the combination, who knows..Reverse has more to do with how deep your motor sits and prop selection.
Since I've never even set foot on a sail boat, I don't have a clue what a prop for one should look like. My transom is 7* I believe. Are you referring to a 2 blade prop?If you get a sail boat style prop it'll reverse great lol. Also the angle of your transom plays into it. The steeper the transom the more it'll just shove water at it.