Props too big mate as i said before as for the offseting to the right it does work but you have two major things working against it ,first your massive oversized in my opinion prop and that picckup hanging below the transom Drag drag drag get the idea .Also been a flat bottomed boat (apart from the runners) ie no vee i would think prop walk could be a difficult thing to overcome as the boat will slide very easyly compared to other boats.Ive ran 5 differnet monos with offset setups and none of them veer right they all track straight,drop a few sizes on your prop piccup a few rpm and your boat will track straighter.Another thing you might try is a subsurface setup which might suit that boat better than surface drive,less prop walk on that setup.If you stick with surface drive you might try the prop eric suggested its a good prop for a mono but id maybe go even smaller myself.
Mart