wheel runout in steam locomotives - Trains Magazine

I just read the article by William H. Johnson and got to wondering if excessive runnout in a driving wheel of a steam locomotive could significantly affect driving pin alignment.

Is it possible for the forces transmitted to a driving wheel by connecting rods enough to cause a wheel to warp over time?

I imagine even a small change in a driving pins angle in relation to a connecting rod would cause an increase in thrust forces by the connecting rod either against the wheel or the nut flange depending on the piston's direction.

What amount of runnout is considered excessive? Is it common, or rare to experience a problem caused by excessive runnout?

Was this a reason for disc drivers in later years of steam locomotive developement?

I have read of rod bushings with a spherical O.D. to allow for missalignment and movement between drivers. Is this a design feature of all steam locomotives or an exception?

I imagine straightening a wheel would be pretty difficult, possibly by carefully heating and cooling parts of the wheel in appropriate places to "unwind" it.

Could wheel runnout significantly affect the dynamics of the locomotive as a whole?

Could excessive heat or heat cycles from regular operation over time cause excessive runnout?

I don't know what kind of answers this will prompt, but I hope the questions are at least interesting and thought provoking.