All I recommend is Rock Slide > Return on Feraligatr, because you'll gain more coverage that way. Other than that, it looks pretty solid! I'd just watch out for DD Tyranitar, since some people like to carry Lum Berry over Leftovers, or can run Taunt against your Blissey, and set up and sweep from there. You can alternatively run Swampert over Feraligatr if you're concerned about the bulk issue against that, unless you'd suspect that it might run HP Grass.
Well, hope that helps; good luck on the tournament! ^^