RE: NEGATIVE ELEVATOR STAB INCIDENCE - NEEDED?
full scale setup is not same as a model setup
don't even try to "calculate" the correct setup
basically try to find the zero lift chord line for th wing - and set the wing and stab RELATIVE to each other by - say - a degree. (leading edge of stab slightly lower than hinge line of stab.)
One degree is aprox 1/4" in one foot.
close enough for folk music.