That's the first Dominator insert pump I think I've seen. Pretty much the same as a Berk JE/JF but with a split bowl.
Ride plate looks a little "cranked way up" there to me, which probably isn't helping, but what kind of power you hitting this thing with?
One thing the regular style intakes have are stabilizing fins under the boat. The JE, and yours obviously, don't have those and can get quite squirrely when enough HP is applied. Berk used to make add-on fins that are attached to either side of the intake opening under the boat and bolted through the hull. Might be some floating around out there, but would probably sooner find an honest politician with the name Obama. So that's out without having someone like Nick whip up custom ones.
It does appear they were trying to force the bow down with that wedge, ride plate adjustment and probably ran the diverter down as well. This would actually inflate the problem, not correct it. This would force the bow down and effectively make the back of the boat feel "light". This isn't a car, it steers from it's ass, different physics and it's keester needs to remain firmly planted in the water. I would lower that rideplate so it is even with the keel to start, flip the wedge around as you planned, and play with diverter settings first. You'll probably end up with a sweet spot with the ride plate in the 1*-2* range up as already indicated before you are done. This is simply a try, test, try again, test again scenario, but sould get you a good starting point.
I would also consider a loader to replace that intake grate.
Ray
Edit: Tha tis a nylon wedge, should be grooved on mating surfaces and no gaskets needed. I habitually use a thin coat of sillycone, however.