I can't say much on the BAS/ESP light, may have to do some searching on the forum (just use the google box at the top). There are several things it could be, even low tire pressure has caused this light for some. The rear tire hitting the well should not have anything to do with this but it should also not happen! If you are not lowered or running non stock rims you may want to check the sway bar brackets and other links on that side. We may need some more info in order to help. (Aftermarket rims? How many miles? Tire sizes Etc.)

There is a procedure for resetting the light after having the battery unplugged. (Turn wheel all the way left, then all the way right and back to the middle) I assume this will not work for you though as it sounds like there is an actual issue if you can feel something wrong. Worth a shot though along with checking tire pressure.