Don't skip the crabgrass control. It should be dissipated enough as to not interfere with seeding in late summer or fall. (When temps fall below 85.) And be sure to research the top quality most disease resistant types of grass you can find. Silver Dollar Perennial rye is my current favorite. I feel that as long as you water-in your fert--the suction bagging system should not remove much of the applied fert. Good luck and let us know what happens. Like Tombo, I am thinking that high nitrogen, during hot humid weather might stimulate disease. This is particularly a problem with brown patch on tall fescue in the upper south.