Covered all of these questions pretty thoroughly in his books, I,Robot, Robot Dreams, Robot Visions and The Complete Robot.

As I recall the Robot politician posing as a human official was a pretty decent guy, all the ideals of the human who built him without the temptation for corruption.

The positronic brains that ran the economy did a great job, so much so that some of their decisions seemed to be errors because they were more subtle than the humans initially understood.

The robot nanny was great, but the mother was all torqued up at it.

The list goes on interesting reads, Asimov was pretty Pro-Robot though.