To say, much less believe, that there are no limits to speech based on the first amendment, is an exercise in futility. There are limits to the freedom of expression in the United States and always have been.
There are severe penalties in expressing yourself in some circumstances. Yelling fire in a crowded theater is a popular example. How about others. Distributing classified material as a means of expressing your distaste of the current state of affairs in the country's dealings with less than friendly nations. Distributing child pornography at all much less in areas that are accessible to children like schools for example.
Using the current thread topic, cursing. How many of you are fully able to use any word whatsoever in the workplace? What would happen if you started indiscriminately referring to women as "ho's" and b***hes, men as "bastards" or the "MF" combination while at work. The same for displaying the same on your clothing when dealing with co workers and the customers (or in the case of public servants) the general population?
How about another example. Religion. It used to be common practice to sacrifice people in religious observances. It was even codified in the bible as an Old Testament requirement of faith. It was also a key practice in several other religions. The same for multiple marriages (Mormonism) consuming the flesh of your family members (or enemies) after death as well as storage of body parts after death to maintain a relationship with the deceased.
If you think these practices will be allowed either under the free practice of religion or free speech I have a bridge for sale, very little used and conveniently located to a major population center. I might also have some Spanish prisoners remaining, please start the bidding soon before the selection runs low.
There is an old saying, your freedom to express yourself stops at the tip of my nose. There is no constitutional guarantee for the freedom to offend, harass, annoy, or endanger anyone else. If you think there is, try some of the examples I have listed above and see what happens.