It is an interesting idea. Still a little unconventional for my taste if for no other reason than resale value. I also have the same concerns as Tom and Michael about the depth of the prop. The problem you'll have is that the lower you make the prop the more it will eat into your usable rudder space, reducing your control under sail. I'm also still concerned about how much resistance you'll need to add to the rudder hinge to prevent the motor from tilting when heeling. That's still going to reduce feel under sail. One more problem when sailing - usually you'd want to tilt the outboard out of the water to reduce drag, but I don't really see a good way to do that here.
All in all I guess as a powerboat it might be doable, but as a sailboat I think it causes lots of compromises.
All in all I guess as a powerboat it might be doable, but as a sailboat I think it causes lots of compromises.