According to the Roman Catholic faith the pope is infallible
No he isn't - it is much more subtle than that. There's no reason anyone outside the RC church should worry about the nuances, but that doesn't mean they should be unaware that they exist.

As for a gay, black, female pope - I wouldn't object, personally, but the odds are very much against it! A pope open to gays, married and women priests is also a long shot, but there's no reason it should not happen eventually, and it could even be this time in theory. I don't know of any such cardinal, personally, but there is always scope for the occasional surprise (Pope John XXIII, for example)