LaTeX is a programming language. Any attempt to refine english to act like a programming language will just result in a new programming language.
LaTeX being a programming language makes it a bad idea for typesetting documents.
I don't see how that follows at all. But LaTeX seems to disprove the notion, since it is, in fact, very good for typesetting documents.
Why should it be acceptable to make flawless translation to other formats impossible for LaTeX if you wouldn't want to do the same for English?
I don't understand your question.
I mean it would be rude to use a natural language that cannot be translated accurately to other languages. So why isn't it rude to use LaTeX to write documents given that LaTeX is Turing complete and cannot be translated flawlessly to other document formats?