If you check in on line and actually print out the boarding passes on the 8.5x11 piece of paper (online only benefit), the coupon appears on there (snack/drink) and the 500 miles is a monday only benefit.
I have never once been thanked for being a DM while sitting in coach this year. I don't personally care if someone comes back and thanks me. Its a nice touch, but especially on short flights, that isn't and shouldn't be in their top priority as I am not the only person on the flight.
zz