Charley, you are right in what you are saying...if taking off was the only thing about flying off water. Mikulasko built airplanes way back then when the biggest engine you saw at the field was a .60 size. Very few had larger things then. The .40 size was most popular. I remember A & A Industries built 1/4 scale planes powered by .60's. They flew but how boring by today's standards. Flying was economical and taking off was great fun along with landing. 3 degrees of positive incidence will certainly affect the flying character of the once the lift off is done. Add engine and it will want to climb, climb and climb even more. Reduce trottle to stop lift and this thing will want to drop...unless you trim for level flight down/up elevator as the case may be. The 3 degree positive incidence on the wing would be acceptable if it is at 0 degree differential with the horizonal stab.
Ok! I'll give in a bit. A .60 may be a slight bit more that essentially needed. However, I still feel that it will require a good .50 +. The Laker has a lot of plywood in it.
Have fun
John