Sounds like you are doing great Bob!
As to the foods issue, one of the things I promised myself was a king cut prime rib just as soon as the pain subsided. Lucky me, my friends called me up and said "we're going" They took me 40 miles to a place with superb beef. That was a great time. For some reason beef medium rare (or rarer) doesn't need much salivia to be consumed!
Let me know if you want me to dryice pack some beef and ship it over.
Tell your wife I think she is great, I thank her.
On the excersise thing, I am not your jock type but I find that streching (yoga maybe) and normal walking (at first) worked pretty well at keeping things in shape. I think an occaisional hard make you sweat kind of thing is ok (like splitting 2 cords of firewood or digging a canal or something), But I would not try much while your food intake is limited. Also make sure you are getting a lot of protein in your food. Your body is having to replace all the good cells in the radiated area at a tremendous rate and it will need lots of protein. (see the beef comment above)
Lastly no one has commented on my blender foods yet and I'm not sure why...I know you can make several thousand calories complete with high protein (lower sugar) and taste a lot better than ensure fit it into a mug and get it past your sore throat pretty easily. It ain't low fat either. Let me know if you have a blender and if you are interested in how to do it.
Take care