Very nice photo essay.
I think you chose the right time of year to visit Myvatn. My one visit there was during the summer, when it was nearly impossible to get within a quarter mile of the shore of the lake for the midges. It's a beautiful area, and I'd like to get back there, but during the winter next time. Maybe I'll be able to get some Hangikjöt!
Mývatn, although a fantastic area, has become too popular for its own good, and with the tourist hordes in the summer it is not only the midges that annoy. But as always in Iceland, you can easily get away from it all very quickly.