I'm rather against (too frequent) attempts to produce FAQ type documents.
There are lots of "systematic" documents available -- for instance, package documentation, books, guides and so forth. I'm all in favour of them, of course, and of encouraging people to use them.
But I think, mostly, a site like this is valuable precisely because it does something a bit different: it enables people to ask specific questions, often based on a particular problem that they are having. Sometimes (often!) that problem could be solved by working through a systematic guide. But for a host of reasons that doesn't work for people. Of course it's frustrating if the only reason is that people haven't bothered to do basic research. But that's by no means the only reason people ask what may seem "very basic" questions: with so many packages, so much documentation, and such a "learning curve" in some cases, it can be hard. So people come here with focused questions dealing with particular problems; the more expert in the particular field can make suggestions, and everyone learns something.
In general the community here is very good about not criticising questions for failing to read manuals and so forth. What we demand rather insistently is something much simpler: that people make their problem clear (for instance with an MWE).
Even frequently asked questions aren't straightforward -- partly because the puzzled novice may not realize that the question they are asking is actually equivalent to another question. The expert can see at once that asking how to convert a chapter heading to a sans serif font, or to make it centered, or to put a line under it, are all related questions. The novice may not. Even when a question is closed as a duplicate, that will often be giving useful information to the person who asked it.
In the real world this is how (many) people learn (many) things: not by systematic study, but by asking questions of more qualified people and gradually building up a store of information and good (sometimes bad!) habits. For many people, this site can be the patient TeXpert in the next door office. And when you consult such a colleague, he or she answers your specific question---he doesn't give you a prepared handout, however good it is.
Turning too many questions into relatively complex FAQs may be counterproductive: it generates long and systematic documentation, which contains material that is both relevant and irrelevant to a particular practical problem. But in many cases it is the difficulties that this sort of documentation has which are exactly the "need" this site fills. It also affects those who answer questions. Having simple questions which are "low hanging fruit" and can be answered correctly and helpfully by many people is a good way of encouraging the sort of two-way participation that the site needs. Polishing an FAQ is a different task.
So, as a matter of principle, I don't think much should be done to discourage questions which are (to the expert) rather basic and even repetitive. Sometimes an FAQ sort of answer will develop quite naturally: that's fine. Often questions will be duplicates, and best answered by cross-referring. And that's fine too. Often it will be possible to refer a questioner to systematic information available in documentation, or elsewhere. But in general I think we do best when we focus on the basic idea that the aim here is to provide practical answers to practical problems, taking (within reason) questioners as we find them, and not aiming too hard to systematize the information available, for which there are other resources already.