New Problem with steering.

[Rileyml1]

2007 Nissan Sentra SER Spec-V
This has been a problem for some time now. It began with me warping stock rotors on the car. When I was at the local track I would apply the brakes and have a (slapping/clicking) . The steering wheel now feels very SPRINGY and every time I go over a hump in the road hit a bump on hard acceleration the steering wheel jerks and the noise comes back. ANY IDEA ! Also note that when the car is off I can turn the wheel to the left and right and it feels springy after maybe 1/4 a turn it seems normal does not stay this way. Also when i am turning the wheel with the car off again feels like I am hitting something.