I think some folks do like to BBQ tofu in its various forms. As for the veg, don't limit yourself!
Marinate thick slices of onion in balsamic dressing or BBQ sauce and grill until they're caramelized.
Any root vegetable that can be roasted in the oven can be grilled. Just brush them with olive oil, sprinkle on some sea salt and pepper, and turn and grill until they're done.
Roast sweet or hot peppers until they blister, put into a sack to sweat, and peel.
You can roast corn in or out of the husk. Out, just husk and roast, turning frequently.
In, pull back the husk and take off all the silk. Brush with soft butter, sprinkle with salt & pepper. Pull the husk back up, fasten the top tightly, and soak in a water bath. Shake out, wrap in foil, and put into the coals to steam.