Fruit Tray(s) - I used your estimates 5 pc/person a mixture of orange slices, pineapple, grapes, cantaloupe adn strawberries
Pasta Salad - 7 quarts (figured 1/4 c serving)
Potato Salad - 7 quarts (figured 1/4 c serving)
Veggie Tray(s) - veggies are consumed heavily here so I just plan to do 2 large platters roughly 13 pound mixture of cauliflower, celery, broccoli, green peppers, tomatoes, cucumbers, carrots
Chicken tender pieces - 15 pounds
Chicken Salad - 3 gallons (figured 1/2 cup serving)
Cocktail smokies - 12 lbs
Sweet and Sour Meatballs - 12 lbs
Crackers - have plenty
Cheese cube tray - 12 lbs (too much?)
Assorted rolls - 1 per person
Sweet Tea - 5 gallons
Punch - 5 gallons
Pound Cake - 110 pieces

Good effort. The zinger here is the 5:30 to 8:30 time slot which means that most people will come wanting a whole dinner's worth of food.

I would do some increases:
1 1/2 times the fruit, add a dip
2 1/2 gallons each pasta and potato salad
30 pounds tenders (yes, it seems like a lot, but these just disappear) plus dips
4 each per person meatballs and smokies
2 rolls per person

Poundcake is a low popularity dessert. If I were doing a gala, I would do 100 each of 4 small (2-3 bite) bars, such as a brownie, a lemon bar, a chesecake bite and a fruit oatmeal bar. This will please people and leave them talking about it.