You sound wicked busy....I'd prolly make as much do ahead food as I could...
Such as:
Enchilada casserole
Mexican Chicken or some such Soup
Prep meat/toppings for make your own tacos
Mexican style Salad (last min)
Guac (last min)
Salsa
(that salsa/goat cheese Traca posted sounds yummy)
Margarita pie
Mexican chocolate cake
brownies with hot sauce/cinn
Sangria
Margaritas
Set a brightly colored table and sprinkle with flower petals (just watched Frieda on tv).