You should baked some bread in the BBQ, just a few minutes ate the end before the rest of your stuff is ready. If you can find some baguette (I usually buy the Costco ones) it's great!
Also marinate (1hour) peppers, onions, zuchini with oil and vinegar, you can put some on a stick, and then cook those on the BBQ.
Dessert is missing in your menu. You should defintely make a fruit salad and bake a cake or a pie. Sweet stuff are always welcome after a BBQ.