It sounds like most of your friends with RVs bought them basically for an indoor bed rather than a full indoor suite. Nothing wrong with that. You just have to figure out if YOU want to use your TT as an indoor bed versus a full suite. It also sounds like you have a friend who is very sensitive to odors - perhaps their advice is colored more by that sensitivity than by the reality of it.
Yes, some smells will linger. But a lot of that can easily be dealt with using advice above (vents, windows, cleaning up right away, taking garbage to dumpster, etc.). The only time I am concerned with smell is if I am camping in bear territory and I'm cooking in the evening when the bears are likely to be snooping around.
Do what is comfortable for you and your family. If you're comfortable doing all your cooking beforehand and then microwaving it, then do that. If you're comfortable using an outdoor grill or fire to cook with, then do that. If you're comfortable using the RV kitchen to cook with, then do that.