Haven't read the most recent responses, but I just had to jump in to say that we just finished discussing (in 3rd grade) how everybody has these rights, but there may still be consequences if you choose to exercise them in a way that interferes with others. I think sometimes we forget that...
I think the determination of "interferes with others" has been re-defined to something that means if someone thinks for some reason that someone might even get offended and I don't want to deal with the circumstances of that I will just disallow the person from the constitutional rights because I don't want to have to deal with someone that is unhappy because of something someone else said or did. That is definitely curtailing free speech.
Yes, you have a right to peaceful protest, but not in the middle of the road impeding traffic. However, that isn't the speech that is the problem, it is the blocking of traffic.
In the case of the dress, speech was stopped because those in charge decided they didn't want to deal with any possible fallout in the off chance that it happened. No one has the right to not be offended.