Sundried tomatoes are great on or in practically anything- salads, pizzas, breads, sauces.
Cheddar powder could be added to other cheesy things like mac & cheese or added to bread or sprinkled on salads or mixed into salad dressing.
Chop and soak the chipotles and put them in sauces, stews, chilis, breads, rice & beans, or pretty much anything that isn't sweet.
As for the margarita mix, that might be good with Sprite or to spice up lemonade if that's your thing. We'd probably toss it in the trash.