Well, you're asking about quite a broad bunch of question categories. But in general, yes, questions about rules and regulations for movie or TV distrubtion, content-rating or censorship seem to be pretty much on-topic here and make for an important part of the film and TV industry, its workings and a work's reception. But let's look at some of your examples specifically.
Rules and regulations for TV and movie distribution, The distribution process (e.g. how distribution networks actually control what I see)
Seeing how distribution is an important part of a film's or TV-show's production, those questions seems to definitely be on-topic here and he have many interesting questions about this, usually tagged distribution. Some examples would be:
Age rating systems, Censorship, FCC (or equivalent) rules
This is also an important aspect of a film's or TV-show's dsitribution and we have tags like censorship and content-rating to cover those. Some examples would be:
Questions about cable companies (e.g. why I can't buy channels individually)
Hmm, that's maybe a little more questionable. If anything, we certainly don't really do personal help-desk-like questions about playing and locating content, or why something isn't on Netflix for example. So if anything, try to not word your questions like that (as your example seems to do).
But asking about the general workings of the TV channel landscape and how it developed or why it is structured that way might be very well on-topic. Just keep in mind that those questions are by their very nature likely to be localized to a specific country. This isn't a proplem per-se, but you should at least clearly specify what TV industry you're talking about and not automatically assume everything works the way it does in your home country (or that everyone is from there anyway).