E430 rear tyres scrubbing on iside shoulder approx 1 inch

I don't have the value to hand but I suggest you either check with the dealer or a local repairer.

Rear camber angle values is not much help without also having the toe value. Any wheel with a camber has to toe in or out by the correct amount or the forward motion of the vehicle will effectively be pushing the tyres sideways robbing the vehicle of power and scrubbing the tyres.

It should be possible to gain a rough idea of the problem from the tyre wear.

Choppy scalloped type wear suggests defective shocks or excessive wheel imbalance.

Wear of both shoulders or edges of a tyre or the centre of the tread indicates incorrect tyre pressures.

If both tyres are displaying a similar wear pattern on the same inside or outside shoulder indicates incorrect toe setting.

If one tyre has a shoulder that is wearing it indicates an incorrect camber angle.

If both tyres are wearing differently the problem is likely to be a combination.

The rear alignment of some cars is adjustable and slight misalignment can be corrected but often rectification comes down to replacing parts or even using a body jack to move mounting points.

I suggest you book your car in for a 4-wheel alignment check.

you should be running 8 ply tyres on the vehicle to carry the maximum load as required by the regulator
The recommended tyre pressure will be on a decal attached to the drivers door ( probably on the door frame under the latch)
Having said all that I recommend 45 psi for the rear and 40 for the front
If you run any less ,the ride will be smoother but if you load the vehicle, the rear tyres are under inflated and prone to failure from overheating
tyres are manufactured to run at a certain pressure due to the construction of the case. Talk to a tyre shop as to the pressure you should be using for the tyres.

this would best be answered at a tyre fitting shop as there are quite a few things to consider , without seeing vehicle

adjust the tie rod ends to achieve toe-in/out adjustment. Measure across the wheels at the front of the steering tyre and then measure across the tyre at the rear of the steering tyre ( same height) and see what the difference is. Adjust the tie rod ends until the front measurement is smaller than the rear by about 1/8 inch . Lock up the lock nuts on the tie rod ends.

If the tyres are slicks on one side and new tyres on the other this is a possible consequence. Check that the tyres on either side are of identical profiles and sizes with approx. the same tread wear.

It varies from car to car but basically it is 1/2 to 1 degree castor --0 to 1 degree camber and 1/4 inch toe in . variations are for road camber-. tyres in use - power steering and load requirements. Always have the rear end alignment checked first as it affects the front settings and tyre wear. Discuss the alignment with your reputable tyre shop

check the sheet metal backing plate just behind the brake rotors, it may be bent and touching when wheel is turned, this is the common problem for this noise.

It should not be a problem as long as he aligns the tires in a four wheel alinement it will be fine, on trucks some axles stick out more on one side than they do the other so don't worry about it, if he's any good he can still align them it's just more work for him.

tyres to big or suspension leaning slightly