There are a lot of topics on this already, however, I wanted to confirm that it is generally considered normal to have water coming up through the centerboard and scuppers into the cockpit when under higher power / heeled / have a larger crew.
I'm seeing water coming in when under power (6hp Nissan at around 50% and higher power) with 4 grown men in the boat (160-200lbs each). When power is reduced below ~50% we're mostly dry.
I resealed the seadog scuppers a month ago and also flipped the flaps around.
I've also found that putting a cork/rubber plug in the scupper where the fuel tank sits helps keep water from coming in there.
Agreed: some water in cockpit when heeled more than around 15 degrees, and several inches once when we had too many aboard (4 in cockpit, 2 in cabin, none lightweights).
You might want to check your bilge though. Water into the cockpit is pretty normal and should run back out. I had leaks though in the piping inboard of the scuppers, and in the centerboard pennant tube. All this drained to the bilge.