Weed control this fall should be OK if you wait after 2 mowings. You are on the right track--looks sweet, Scag. Rotary mower should be OK. Don't let it get too tall--taking too much off the top shocks the roots. Cutting helps it to spread sideways. Additional fertilizer 4 weeks after seeding will help it thicken up. Push it. Get it thick now. Do not plan to seed in spring as the crabgrass pre-em will kill new seed.