It will help you a lot if you read the data correctly, and don't rely on the seat map.

For example, on Flt 27, next to Available First Class Seats, it says Not Available. This means none are for sale, and the cabin is full.
On Flt 41, it says 3. While you may see 4 seats on the map, someone hasn't chosen a seat yet. (likely an upgraded pax)

And yes, off-peak times will be your friend. Mid-week and Saturdays in business markets usually carry a lighter load, but summer travel will be here before you know it and that will make a difference too.