"and all I'm saying is that if you're going to have a litany of exceptions, then put them in the damn constitution/amendment."
A seemingly reasonable request, but I suggest:
Nooooo! By all means, do NOT do this. This is bad governement as exemplified in the mess that is the Louisiana state Constitution and its multitude of amendments voted on by a mostly uninformed electorate. One of the genius features of the republican form of representative democracy is that it avoids such problems. Of course, this is so just my opinion, man, but it is an opinion shared by many of the Framers.
A final point: The obscenity construct is of judicial crafting and represents an attempt to define the boundaries of First Amendment protections that were never understood to be literal or absolute. I would prefer for the judiciary to come up with a better construct, over time, than deal with an Amendment process that could make things worse. For example, what if the amendment clarified the First Amendment by protecting only political speech such that it became crystal clear that artistic speech was not protected at all? We may not be able to define its contours with precision but we still have a constitutional protection of speech that is pretty robust and I would hate to endanger it.