I can say that he's not the most comfortable-in-front-of-a-camera person I've ever photographed, but I don't think they are that awkward. I can certainly take most of the blame for the posing though. I only gave them minor direction in terms of posing and it's the photographer's job to help 'loosen them up' and make them comfortable during the shoot. That was actually the idea behind the tank shot, it's to help make the session fun and get them involved etc.For some reason, these seem very awkward to me. Also, the white balance on the color photos feels/looks cool to me.
This might be a bit beyond the scope of a typical session, but did you get any soft of vibe that the couple was having any sort of personal problem at the time of the session?
I think you are inferring way too much by suggesting they are having problems. They seemed to me, to be very much in love. I did get the feeling that they are not much for PDAs (Public Display of Affection) and of course, they are not 18 year old H.S. sweethearts. This was the 2nd time I've met the groom, and he was a fair bit more comfortable this time.