5. I don't think we have anything like Monty Python's Flying Circus.
Britain has a plethora of sketch comedy groups, many of which have been given their own TV shows, but yeah, I can't remember ever seeing anything similar on American TV. Saturday Night Live seems to be the closest you have, although the cast is constantly changing on that, it does feature a fair bit of absurdist comedy though.
Kids in the Hall remind me a lot of Python, although they are Canadian of course.