Prepping to freeze, thaw and reheat
This is a difficult question in part because you've listed so many things -- for instance, a cream sauce is going to be difficult, as cream sauces may break when frozen.  Cooked chicken, on the other hand, I go quite frequently.

But the thing with the chicken is that I'm cooking it to use as an ingredient in other things; I think you may have more success in that way -- compromising between the two by prepping and freezing some items to minimize the amount of work needed for each day's cooking.  Some foods benefit from preparing in advance (stew, chilli, soups, etc.) that may could from once a week cooking.  You'd likely want to bring things back up to temperature and then adjust seasoning on the day of.  (possibly adding fresh herbs for the ratatouille and/or a splash of extra acid to brighten it back up)

I don't know what sort of food truck you're operating; if it's one with a kitchen, or if it's the type that prepares food in a canteen and does no cooking on-site ... I'd assume if you're cooking on site, this could be a problem as it'll take more time to cook from a frozen state.

It's probably worthwhile to do some taste tests -- make a recipe, then put some off to freeze, then thaw it back out a week later to compare to fresh and/or canned.