I understand your frustration, but just to play devils advocate...your OP is sort of confusing. You say 'please watch what you say'...but then you say, 'please do not walk on eggshells when you talk to me'. Maybe this is just a situation where people want to be friendly but since they are not in your situation they do not realize what would and would not be offensive to you?
I mean, you admit that you really do not believe that people mean any harm by their comments, so maybe you could consider that and chalk it up as their having lack of personal experience?
I guess what I am saying is that no one knows what you have heard a hundred thousand times. So, maybe they are engaing you in conversation (in a lame way) because they want to be friendly?
I dunno. I understand venting, but your post leaves me with the impression that I should just ignore people in wheelchairs, or at least referring to their wheelchair at all, because I might say something that offends them in some way.