Anything that isn't scalable. Taleb writes at length about this difference in The Black Swan, categorizing professions in which there are winner-take-all effects (Extremistan) and low variance, stable, one-sample-is-representative ones (Mediocristan). As you said, surgeon (the example Taleb gives is 'dentist'), prostitute, taylor, and so on. He also notes that some professions can switch categories, e.g. musician, since the existence of recording technology the distribution became a Pareto one.

Depends. If surgeons somehow ended up working for a company/franchise then that company will hold all the power. Surgeons would have to unionize to get some power back.

I hear that something like this is happening with vets.