That's not how this works. The constitution and amendments are the foundation. There are centuries of supreme court rulings and further legal precedent that determine the modern framework.
Actually, it is how it works. You are confusing case law with what k_sh actually claimed, which was specific exceptions. There do exist U.S. constitutional provisions with specific exceptions, such as the 5th Amendment. The 1st Amendment is not one of them. Indeed, it is famous for being neither specific nor having clear exceptions.
Contrast with the Basic Law of Germany article 5, that has already come up in this discussion, which outlines specific exceptions in paragraph 2. (For another example, see article 8.)
Incorrect. What is being discussed are the applicable rules to citizens today, and the cumulative legislation states that there are exceptions. We do not follow only the constitution and bill of rights, otherwise what do you think the thousands of other laws are doing exactly?
Real exceptions exist, regardless of whether they are written in the original amendment text or in rulings afterward.
The amendments themselves are not in the constitution itself, so do they not apply?
Amendments were added to the body of laws after the constitution, and congress and the supreme court have since added more to the body of laws after the amendments. The cumulative result is what governs citizens today.
Those laws are in fact very specific about their exceptions, as shown very clearly in the wikipedia link. What exactly do you find fuzzy or confusing about them?
Case law, as you linked, is not. It also keeps changing without the underlying documents changing. I don't know how you can look at all those dates marking times high courts had to get involved and still say it's clear.
Free speech does have certain restrictions, which you can easily read about here: https://en.wikipedia.org/wiki/United_States_free_speech_exce...