I have fished out of a boat just like yours for 3 years, You don't need treated plywood, put some sealer on it, Im talking from Exp. here,
you don't want to raise that floor up any higher than 2+2 , Will make it, Unless you want to spend all your time fighting to stand up!!
My little boat is all electric, I cut the top out of the middle seat, Made a 'cap' for it with plywood, I have two Big Bat. in there, 55lb motor
on the back and 28lb on front, Thing really moves around good!!
Back to the deck, I stand on mine all the time, Alone, wouldn't want to do it with anyone else in there!! My boat is a 10-32 Tracker
if yours is wider(at the bottom) it might not be so "Tippy", Mine was new when I did the Mod. on it, Didn't paint, but there is a lot of
advice on that in here!! Anything I can tell you to help, post it!!