This is an easy issue to rule out, all you have to do is find a tire shop that has road force balancing. It puts the tire against a rolling circle mimicking tire on road if you will which then identifies if the tire is out of balance. A lot of times tires get flat spots before being mounted or develop flat spots by sitting for a long period of time. There isn't a fix for it you will need to replace the tire. Uneven thread will also cause vibrations. When you have a shake in your steering wheel at speeds it can be variety of issues, control arms, ball joints, rims, balancing, tires, uneven thread, wheel aligment etc etc. But you start at the cheapest option first, get the car lifted and have checked out control arms and ball joints, then go get all wheels road force balanced, etc etc