I'm anti-PC and agree with everything you've said.  Why do people have to be so worried about offending people on accident all the time?  I believe I know when a person has good intentions and when a person has bad intentions.  So it comes down to this: it doesn't matter what you say, it's what you meant by it that matters.  If you meant to hurt or insult a person, then it's wrong.  If you were just telling a silly joke or said something you didn't think was bad, then you shouldn't be in trouble or fired for it.

BTW - As someone who is 50% Arabic, 25% polish and 25% irish, I hear (and make) lots of jokes that I laugh at.  But one time someone I worked with said something I couldn't believe.... she said to a black girl "well I'd rather see you blacks moving to town then those arabs".  Offended us both in one shot!  We looked at each other and just had to laugh b/c it was so outrageous.  I don't think she knew I was arabic but even so she indicated that the black girl was only slightly better than the arabic people.