Earlier quoted context omitted.
Idiomatic translation of text matching a human professional (e.g. free of errors for legal terms, interesting and natural for fiction) is unlikely to be achieved until we have AGI. So no.
I won't comment on the first bit as i've not personally tested in that are but GPT-4 can absolutely make short work on the second. I don't think people realize how good Bilingual LLMs are at translations. Yes you have idioms transfer between languages. Feel free to test it yourself.
This.
GPT/ChatGPT is able to even translate between different "accents" or dialects of the same language. For example it can give you the same sentence in Mexican, Argentinean or Peruvian Spanish.
Example:
Me: Give me a sentence in spanish that is different in Mexican, Argentinean and Peruvian Spanish. Write the sentence in each dialect.
ChatGPT: Mexican Spanish: "¿Qué onda, güey? ¿Cómo estás?" Argentinean Spanish: "¿Qué onda, boludo? ¿Cómo estás?" Peruvian Spanish: "¿Qué tal, causa? ¿Cómo estás?"
These sentences mean "What's up, dude? How are you?" in English. The primary difference is the slang term used for "dude" or "friend" in each dialect: "güey" in Mexican Spanish, "boludo" in Argentinean Spanish, and "causa" in Peruvian Spanish.