I found an answer to my own question, but it's rather inconclusive.
What I'm describing in my question is what in linguistics is seemingly known as an anarthrous nominal premodifier (aka: a pseudo-title, a false title, a fake-title) [see Wikipedia]. They do exist, but they aren't regular titles, as they are not capitalized (~usually~). But they do act like titles in any other way.
They are primarily found in newspapers, which is where the problem arises. Newspapers have style guides, specific style guides. So some newspapers (e.g., New York Times) don't even allow a writer to use them, whereas others even encourage it. The same holds true for linguistics, which also can't decide, if pseudo titles are okay.
That's really the point: Is it okay to use pseudo titles: I don't know, no one really does. Unless you plan to write for a specific newspaper, where you can check their style guide, the answer is to do whatever you want, but keep in mind that pseudo titles might sound more colloquial and American.
Oh, and technically no one did really ever mention in the talk about pseudo-titles words like friend, but @FumbleFingers found at least a few occasions of the word husband without any article or pronoun.