To me, most of the examples above are things that could be offensive, but not really violations of 'political correctness.' As the wikipedia quote above put it well, PC is avoiding offenses against an identity group; that is, things that could be seen as racist, sexist, or otherwise bigoted.

Generally, the issues I see that stride across that line include racial and religious fetishes, and gender-defined roles.

I can't personally understand how anyone can have a racially-centered fetish without having some assumptions about the role of race in society. But then, I've never had a chance to talk it over, either. Either way, every porn gallery seems to have a section of inter-racial stuff, often larger than the bdsm section.

Gender roles would be more than individual cases of top and bottom...it would be the assumption, for instance, that all women have submissive tendencies or should be dehumanized. That changes the discussion from a specific case of power exchange (however offensive it may be) to bias or preconception about others. This is often a 'charge' levied against Gorean advocates, for instance.

Other issues could be cultural or religious. I just posted a series of burqa-centered pornographic images, for instance, which could be interpreted as an attack on customs or beliefs. Other fantasy images or scenarios -- such as the naughty nun or pedophiliac priest -- could be intended or interpreted not simply as pornography but as a broader prejudgement of an entire belief system.

All this said, I'm not entirely sure how beneficial the PC phenomenon is; layers of censorship regarding minority groups seems unlikely to lead to equality, but we should at least be aware of when we're offensive and why.