Wow, tough one.
I would only help these folks if they really wanted to change things. This should be easy to determine. I have found that most folks in that sort of environment really don't want to make the effort to change.
First off, for the severely detrained, getting off your ass and walking around is the first step. When travelling, if they have an opportunity to relax and go for a decent walk or hike, then they should take that opportunity. Even playing 9 rounds of golf without a cart is a good start.
Second, the resistance part is going to be hard. The percentage of the population who actually will train in their hotel room or while on a business trip is small. I can think of very few people who'd actually do a workout without someone supervising them.
Other than that, your ideas seem very good.
Diet: Meat and salad. Low carb if possible. Meat, eggs, fruit, veggies if not.