Well, again, you don't need to aerate, but it doesn't usually hurt anything. Mother Nature never aerates Her grassland prairies or savannas.

You are mowing perfectly.

Weed n feed is not a great product. Why? Because you need a weeding product in mid April and you need fertilizer in late May.

Spring is not the time to reseed for PA. Late summer is the best time. Generally that varies with latitude, so late Sept to late Oct is good. Since you have clear dead spots you likely don't have any Kentucky bluegrass in the lawn. KGB is a fun grass to have because it loves full sun and will spread out to fill any thin areas. One thing people don't like about it is it can turn brown during winter dormancy. That doesn't have to happen, but it does for most people.

One problem with bare spots in the lawn is that rain can pound directly on the soil and leave it compacted. Rather than using an aerator, I would suggest spraying the entire lawn with shampoo at a rate of 3 ounces per 1,000 square feet. Three ounces is the minimum that works very well. You can use more without hurting anything, but there's no special value in using more. After you spray the shampoo follow up with 1/2 to 1 inch of water from rain or sprinkler. You can use any shampoo that is clear enough to read through. The stuff from Dollar Tree that smells like apples is fine. The shampoo takes the place of core aerating. It works by allowing water to penetrate the soil much deeper creating a moist environment deeper in the soil. This is the environment that the beneficial soil fungi love. It's those fungi that do the aerating and softening for you. One application of shampoo can last you for many years, and it only costs a dollar or two.

The first fertilizer of spring generally goes down in late May (Memorial Day). The next app can go down in early September (Labor Day). The next/final app can go down in the Thanksgiving time frame, but this one is a little more particular. Wait until the lawn goes completely dormant, and then apply something like pure urea at the bag rate. The reason for waiting is so you don't get new grass shooting up right when it's going to be freezing for awhile. The fertilizer applied this way works on the root zone filling the roots with nutrients which will last you until late May. Just because all the stores are selling fertilizer in February doesn't mean you have to buy it then. You could buy it then, but don't apply until late May. If you are not already using organic fertilizer, then I would strongly urge you to add one app of organic. If you really, really want to apply fertilizer when everyone else is in early spring, then use an organic one then. With organic you can apply it any day of the year, or every day of the year, even on the day you apply a chemical fertilizer. Rain or shine is fine. It doesn't need to be watered in like chemical fertilizers do, but a little sprinkle will get it started working.

When you reseed seed the lawn, I would suggest a triple mix of fescue, KBG, and rye. The three types of grass have similar and different characteristics which interact to give you a nice lawn, and minimizes hassle. Scatter the seed on top of unprepared soil and follow up with a roller or simply walk on the seed. Water it very lightly several times a day to keep the seed and the SURFACE of the soil moist. You do not need to saturate the soil. You also do not need to fertilize the day you reseed. Seeds carry enough nutrients to feed a new plant for a month. If you wanted to use an organic fertilizer at seeding, that would be about right, because organic fertilizers take about 3 weeks to kick in and become available to the plants.

You do not need to use expensive organic fertilizers. If you read the label on organic fertilizers you'll see they contain real food like corn, soybeans, wheat, and other ground up nuts, beans, and seeds. My favorite organic fertilizer is alfalfa pellets (rabbit chow) and ordinary corn meal. You can get these at any feed store with the possible exception of Tractor Supply. They have similar feeds for fish, chicks, goats, etc., but they have a lot of other stuff that jacks the price up. The application rate for these grain type organics is 15 to 20 pounds per 1,000 square feet. When you buy the ingredients for organic fertilizer from the feed store it costs about 1/7 what it cost in a commercially bagged product. Organic fertilizers take a full 21 days to kick in, so don't get impatient. Most times you forget you applied and then, "suddenly" the yard is deep green, dense, and growing fast. Here's a picture of mrmumbles lawn after he dropped a handful of alfalfa pellets in mid May. The picture was from mid June.