I'm interested in the phenomenon where people object to "illegal" as though it is inaccurate because the person implied by "immigrant" cannot be illegal in merely being a person. While moral and legal objections may be harder for those in society to come to a definitive conclusion about, I'm pretty sure that purely linguistically speaking, there are plenty of cases (even prescriptively accepted ones) where an adjective is accepted as modifying the noun, particularly one with a clear relationship to a verb ("immigrate") where the modification is more as an adverb of the verb from which the noun may be derived rather than of the noun itself (e.g., "illegal immigrant" need not be understood as "immigrating illegal person" but instead simply as an "illegally immigrating person"). Is there a linguistic term for this kind of indirect qualification?
I'd also be interested in an exposition about this discussion extending to adjective + nouns where the adjective is even more indirectly acting as a kind of adverb for a verb implicit in the noun--such as "illegal alien" (where "illegal" describes the manner by which someone is or became an alien).
(As a bonus question, it'd be nice to have a few more examples that are similar, even if having nothing to do with social issues. I can think of "hard worker" where "hard" describes how hard the person works, and not that the person who works is hard-hearted or has tough skin.)