A video would really be helpful here. You can upload it to YouTube and paste the link to it in your reply here. But the short answer is yes, you can change the location of the horn to move it away from the motor. This will require you to change or adjust the steering link, and it will likely not...
Not going back to center in one direction is a sign of worn gears in the servo. Is it not centering from the direction it is hitting the motor? Do you know how to set servo endpoints for your radio? Endpoint adjustments are used to set the maximum servo throw, to avoid damaging your servo...