John

My advice is to get the radiation because the major risk of radiation is not getting it at all and then having those microscopic cells left over from the surgery bring the cancer back. This risk of not having radiation more than outweighs any possible complications. Otherwise you will never forgive yourself if the cancer does come back.
Use the insurance analogy: you always insure what you can not afford to lose: your house and your life. Trust me, some dry mouth issues and potential taste issues (both of which often and regularly resolve with time for many here) would be the very least of your worries if the cancer comes back.
I know you are emotionally overwhelmed here (okay, I don't know that- I'm just remembering that I was when I was facing a similar choice to risk getting a second round of radiation past the "maximum"), but having to sip water and finding some things bland is most definitely does not amount to "lose it all" in my book. That will be if you don't get the radiation and it comes back.
I wanted to make sure you have a clear idea of the real risk: joining the recurrence club here
Charm