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The E to Jamaica Station is faster than the A to Howard Beach if you're north of West 4th Street and I've always found Jamaica to have more people milling about, which I'd find comforting if worried about safety. You can take the A or 1 train down to 42nd street and then switch there to an uptown/Queens E train.

With no checked luggage and boarding passes printed at home I'd aim to arrive at the terminal ~75 minutes prior to my flight that day. That means 8:15a for you. You should be able to walk out your door between 6:45-7a and do that on the subway/AirTrain no problem. The chaos at the airports for Thanksgiving Wednesday travel usually doesn't kick in until a bit later in the day.