In my experience, cider is a bit contextual. I've heard and used it to mean both alcoholic and non alcoholic cider. But usually people default to mean a non filtered apple juice like you said. (Since we also have apple juice, but it's hard to think of it as anything other than super processed sugary drink)

Apple liquor/cordials are usually called just that, or more specific depending on the type of liquor (i.e., my family keeps a bottle of Apple flavored whiskey)

Things like apfelkorn probably just get wrapped up in the catch-all term schnapps, if not one of the above terms