You decribe two different systoms and it decribes two different problems both of which are enough for me to send you looking for a shop. Your first is a bad tire they start to wobble at 15 and normally quit at 25. The other would be your left front caliper holding the rotor to tight. This could be caused by several problems. The first most common problem would be the right front caliper not working properly and causeing the left to try and lock the rotor, second could be the left side rotor warpped causing heat buildup in the left rotor. There are a few other items that can do this but thoses are the most likely. You need to seek out a good shop and let them put an eye on the problems.