Cobb, you should have every right to wear a kilt to work in my opinion. As long as you have the legs for it.
As for the high school issue, I support school uniforms. I think that would eliminate this problem and a lot of otheres that are draining people's focus and energy away from education.
I don't think "freedom of speech" covers every situation. For example, I don't have a right to tell racist or sexist jokes in my workplace or otherwise harass my co-workers even though I could argue that it is a form of free speech. The reason is that my co-workers HAVE to come into the workplace with me every day in order to continue to keep thier jobs and earn their livng. They shouldn't be subjected to that kind of treatment. If I am telling the same jokes on a street corner, then people can simply choose to walk away, so my actions there are less of an infringement on other people's rights.
School is or at least should be the same way. Just because you have a constitutional right to say it or display it in public doesn't mean you should do it in school.
I wouldn't say that the word "vagina" is necessarily offensive or disruptive in itsself, depending on the context, but which side of the line that word falls on really isn't the issue here. The issue is more about whether the school has a right to set and enforce policy about this kind of thing. And clearly they do and they should. Any policy guidelines will invariably mis-categorize some things at the margin, but that is inescapeable. If you allow "vagina" in this case, you have to allow "*****" etc. and if you allow them in the context of women's issues, then you have to allow them in other contexts as well and you can see that it becomes a slippery slope very quickly. It is more practical to just draw the line in a way that is easy to understand, follow and enforce.