7 beardies at once does not seem like a good idea. If they got distracted, I would think all chaos would break loose. My husband and I have 3 beardies, and we would never take any of them into Walmart. It's not sanitary and it would be too cold for them.
We have taken them to Petsmart, Petco, the park and a friend's house. But when we do take them anywhere, it is 1 at a time. We could never take all 3 at once because they would fight each other, or go after the female.