I would highly advocate that yes, such questions are off-topic, because we cannot reliably answer them and because the answers may depend on a number of other factors, such as jurisdiction and additional facts. Determining which questions are under this umbrella is, of course, more troublesome, as some questions may have "legal" and "non-legal" components. Borderline questions that may or may not be OK could include:
How can I avoid asking interview questions that are discriminatory?
What should I do if a co-worker is harassing me and my boss/HR/whoever will not do anything about it?
Questions that are pretty clearly "legal" in nature (and IMO should be off-topic) might include:
I was injured at work. How do I get compensated?
I believe I was passed over for a promotion because of my race. What should I do?
Clearly, none of my examples are spectacular questions anyway, but I hope that my point is clear. Where should we draw the line, and what should the FAQ say?