As was posted, the dot should line up with the valve stem but it's not a big deal if it isn't. Even with the cush drive, they should have checked the balance. However, most modern tires and wheels are so well balanced that they take very little weight anyway.
Buying your tires elsewhere is a bit of a sore spot with me. My shop will not mount tires that weren't purchased at our store. First off, what happens if the tire is defective or there is a problem with the bead or it doesn't seat properly? We can't get it replaced for you but you are going to expect us to. Why should we take the liability of being associated with a tire that we made no money on? Besides, you don't bring your own ground beef to McDonalds do you?
Rarely is the question stupid, but sometimes the answer is
you need to run everything you read online through your own personal BS meter to determine if it makes sense to you.