I've been flying to Calais with my wife and / or friends for several years now and seen the ups and downs. But we walk down to the Marie or a little further to the main road in Marck and catch a bus into town. True, they are not too frequent - one or 2 an hour. The bus used to take a diverse route but is now back to a direct one -it takes 15 minutes and costs 1€ per person. We get out at Theatre.
Once in town there are various shops, the War Museum opposite the town hall and some excellent restaurants. A little Ballotin bus runs up and down the main street every 10 minutes or so and is free. At the end of the main street, close to the ferry port, is the restaurant Le Channel, where we had an excellent meal recently. There are other good restaurants nearby too.
Close to Theatre is a smallish shopping mall that has a Carrefour and is useful for saving a € on a bottle of wine! You catch the return bus on the E-W main road by Theatre.