In other words, when you study a natural language, you must learn which metaphors are allowable. When you study an AL, you must learn to not use metaphor at all, which is much easier. As for the pointlessness of trying to avoid metaphor, think again. I doubt if anyone will have a problem with these metaphors, since the concepts are simple and involve easily visualized and well-understood physical entities. Different people will interpret it differently, depending on their world-view.
Professional translators are very much aware that metaphor almost never translates.
Sometimes it simply sounds like gibberish. At other times, the metaphor is completely misunderstood. If you have any doubts about this, then spend a little time at a library and look up some books on the theory and practice of translation. The book has a chapter on metaphor, and discusses the difficulties involved in translating them from one language to another. In other words, a simile is one of several types of metaphor.