Robbing average Joe is universally considered wrong. Robbing bankers, insurance companies or other powerful subjects, I don't think so. It depends on the circumstances - for a good example, see the movie, that is, if you like such a mental challenge.
Yes it is.
Maybe you live in an interesting developing nation?
Robbing banks, stores, anyone - is considered basically immoral in all of civilization, thankfully.
Yes - not all bank robbers are psychopaths - probably not the majority.
But prisons are fully of people bending reality to justify their crimes.