There is a certain amount of natural slack within the steering box. This is a fundamental part of how they work

My wheel sits at about 5° to the right, which seems to coincide with steering one handed, arm on door, and holding the car straight against the camber, especially on single carriageways. It would seem that this is the steerings natural straight ahead position

One of the most critical angles on a rwd car is the Thrust Angle. It is basically the direction that the drive axle pushes the car in. It needs to be as close to 0° as possible otherwise the car will crab, as Entwood has already pointed out

As long as the pitman arm and steering idler are exactly parallel to the chassis rails when the casr is set up, then it will always run true on a smooth, level surface

Tyre wear is a good indicator of failure of any bushes/joints, but over time you can expect the front tyres to wear both edges, and the rear tyres to wear centrally. This wear, over time is perfectly normal

Any wear which happens suddenly, ie over a couple of days to a week is a sure sign of a problem

If your car drives straight and your tyres are wearing evenly, then you have little cause for concern
