The suggestion given in the Harvard admissions blog states: "Of course, we certainly understand that some applicants have been out of school for several years or might otherwise be unable to secure a letter from an academic source. In such instances, we suggest asking your professional reference writers to comment on qualities and skills that can translate to an academic context."

So just pick someone who can speak to that and ask them specifically to touch on how the qualities and skills they witnessed in a professional environment would translate to academic success.

The noun can be two words. The easiest example would be a proper name, like George Washington, where obviously neither word modifies the other. In science fiction, though, science is talking about the type of fiction; consider that you could swap out "science" to read "historical fiction" or "poorly-written fiction" or anything else.

But I think the key, as was mentioned in the video, is to not get too hung up on the actual grammatical analysis. The whole point is that you understand the sentence, and in this instance, choosing science fiction as your subject rather than just fiction probably doesn't detract from your understanding.