Tires wearing super fast...Help!!

Halfkiddio

Basically you're looking for any excessive movement in the whole assembly. You can do that by shaking the wheel left to right to check arms and bushings, and up and down (lifting the wheel straight up. Best done with a jack handle or pry bar.) to check ball joints and wheel bearings.

You really shouldn't have any movement in any direction front or rear, so anything more than 1/8" is excessive. If you get movement, start tracing it back, working your way from the outside in.