Chicken and noodles- could skip? If not, 1/2 cup per person- about 6 gallons

Potato salad- suggest you skip, since you have the cheesy potatoes and the noodles in the chicken.
Mac salad- 6 pounds dry pasta per 100

cheesy potatoes- see recipes and calculations at the recipe at the end of the festive family brunch page-

Broc, Carrots & cauliflower raw veg trays
About 6 pounds of carrots and 3-4 pounds each broc and cauli per 100. Consider adding a few quarts of cherry or grape tomatoes for color. 1 cup Ranch dip per 5-6.

grapes, strawberries, pineapple mixed fruit.
You want about 6-8 pieces of fruit per person, see the fruit tray page. You might add a seedless watermelon or 2 to increase pleasure and reduce costs.