It's amazing how efficient a little air pressure is at preventing pinch flats. That might the first issue. Don't underinflate. OTOH, as soon as folks start using terms like rolling resistance it's a beacon for over-inflation, which doesn't help either.

+1 on Schwalbe Marathon (+/- Plus). Perhaps in the 1.6 - 1.9 range given your rims and mass.

And I have learned that tread is over-rated.