Is this enough food? I stuck with my sons favorites and I was going to add mac-n-cheese too but wanted to check in with you. Or...what about adding antipasto?

I would definitely NOT add another starch dish. A relish tray or antipasto tray or antipasto veggies are indeed a much better choice. Recipes for all on this site.

Meatballs (estimating 2-3 per person) about 14 pounds
with 4" rolls (13 dozen) plenty
Consider 3-4 shaker cans Parm, 8 pounds thin sliced provolone
Pulled pork sliders (18 pounds)
extra dinner rolls- ? just allow at least 1 1/2 4 " crusty rolls per person,. about 15 pounds all together
Need 6 pounds thin sliced onions, 3 quarts pickles, 1-1 1/2 gallons thin shred slaw
Chicken Riggies pasta (2, pans - restaurant says will feed 60 people)-plenty
Mashed Potato bar (20 pounds potatoes - using your recipe )and various toppings- plenty, you can use the baked potato bar topping list for this, 1/2 the amounts for 100
Cucumber, mozzarella, and tomato salad (estimating 5-6 pounds)-way short- at least 1 pound per 8
Pasta Salad (8 pounds dry)- 6 would be plenty, prob some left
Fresh fruit trays - 2 trays estimated to feed 65 people (each?) I would do enough fruit for everyone- you could add chunk fresh watermelon to the prepared trays if they only total 65 people- 20 pounds?

Your desserts are plenty. Consider doing dinner level coffee for the adults with these nice desserts.