Some of your questions have been answered. Which is great everyone here is very helpful. There are other nutritional options the ensure is great. You can also pick up a protein powder to mix into a smoothie or if you get an unflavored one you can toss it in soups. They have chocolate, vanilla, and berry flavored too. Often one scoop is 25 gms of protein - he'll need a lot to heal.
The smoothies - you can add fruit and yogurt and ice cream.
Smoking is not a good thing - it would be best for him to quit but again you've already got a lot on your plate and frankly he'll either do it or not.
The type of chemo - I meant the name.. Cisplatin he'll need a lot of fluids. It can mess with his hearing - and is hard on the kidneys.
Let me clarify - is he having chemo once a week for 5-6 weeks?
(The other chemos are
Erbitux, or carboplatin - these are the most popular)
Someone answered your question about the cream so that's great. I used to apply it directly after radiation and a few times later in the day, and once before bed. If he's fair skinned he may burn and blister badly, if he's darker skinned or olive skinned he may not have it as bad.. I tanned mostly. Had this funny tan from my nose down...

Anyway best of luck...