Good luck, dtm74!
To help answer two of your questions, I tried to maintain my swallowing, but usually by halfway through my treatment(s), I would need to rely on my peg tube, which I had for several years anyway, so it wasn’t a big thing. Even with that, it was still difficult for me to reach my nutritional goals, and mostly depended on areas radiated, and type of chemo I was having, sine were easy, like smaller radiated areas in my neck, and lighter chemo, while larger radiated areas, and stronger chemo’s and targeted therapy, were more difficult, for me,,with prior treatments.
Everyone can be different! Whatever you think would help you through treatments, use, as long as approved by your doctors. I found hydration to be important, maintaining swallowing as long as possible, and maintaining mouth exercising, even if relying on a peg tube, and rest! At Hope Lodge it was good being around different cancer patients, and activities, that you could tolerate. I think I did more with a group, than when I stayed alone at home!
Good luck!