Preheat oven to 450 degrees F. Roll pizza crust into a large rectangle, about 14 by 10 inches.
Top pizza with barbecue sauce, to within 1/2-inch of the edges. Top with onions, shrimp, bacon, olives, and both cheeses. Bake 10 to 12 minutes, until cheese melts and crust is golden brown.
Meanwhile, in a small bowl, whisk together the cider vinegar, olive oil and Dijon mustard. Stir in the raisins and the crumbled blue cheese. Season with salt and pepper and toss with the packaged coleslaw mix in a large bowl. Serve with pizza.