Two or three degrees at the most. Remember what angle you want the floats to be in a landing attitude. If the plane or you like to land at a flat attitude and you have 7 degrees built in, the nose of the floats might try to dig in on landing. The floats should be either flat or a degree or two positive on landing.

CG is more important and should be on or slightly forward of the step. Re-read the "Newc" reply about balancing.

On take-off in a full scale plane on floats there's a "Sweet Spot" you're looking for. It's when the aircraft is just balancing on the step with no drag from the bow or dragging the heels in the water. With enough speed and flying the "Sweet Spot", that magic thing happens. You shouldn't have to fly at max speed to lift off and you shouldn't need a lot of up elevator.

I used to challenge the peanut gallery on the beach to shout in unison when they all thought my Seamaster had left the water. I didn't have to pay up once! Fly it off and be smooth about it.