I want to address the last part of your question, which was about how we handle questions from non-native speakers.
ELU offers gets questions that are quite obviously (based on their content or writing style) from non-native speakers learning the basics of the language. Those questions usually, and quite rightly, get migrated to ELL instead.
The reason for these migrations isn't that such questions are "too easy"; that isn't an acceptable reason for closing questions, now that we've made the decision to remove the "Not enough research" close reason. The reason why we migrate these questions is that the two sites have different goals and different target audiences, and thus a question from a non-native speaker will simply get a better answer if it's posted to ELL instead.
A good answer on ELU is one that is technically correct, i.e. consistent with modern approaches to English grammar. A good answer on ELL is one that is useful to learners, providing practical advice for someone who wants to be able to communicate effectively. In other words: if the ideal ELU answerer is a linguist, the ideal ELL answerer is a language teacher.
With questions like yours, I think the most relevant question is: is it a question that a native speaker might also ask? I think the answer is quite clearly "yes"; I'm not entirely sure of the answer myself and would be curious to know. This could be answered by careful research looking into etymologies of some of the terms in question (research that the woefully inadequate current answer has failed to perform). In many cases, as with "cold blooded," the origin has nothing to do with weather conditions!
Was FumbleFingers making a bigoted assumption that defenders of Palestine can't be good speakers of English? I don't think he was actually making that claim, since he surely knows that a very large number of native speakers share the same sentiments. I think he was instead saying that the question's writing style (before the recent edits) suggested it was from someone unfamiliar with the language; that would be a reason to migrate to ELL in many cases, but I don't think they necessarily apply here, particularly because the question is about the language's history, not about how to use it in the present day.
Of course it is completely unacceptable to close a question because you don't like someone's username or profile picture. If you think that someone's profile is offensive in such a way that it violates the site's policies, that could be brought to the attention of a moderator. But "Free Palestine" is not, to my knowledge, against any such rules; it's a straightforward expression of a very common political view, and it's not inherently an endorsement of violence, bigotry, or hatred.