He was a philologist who oversaw translations during his lifetime and even wrote a guide for translators to use when translating fictional names. It sounds like he was picky and critical of translations, but not because he didn’t want them to exist.
Maybe I'm being a bit naive, but intuitively I would think that most writers do not write a book with the explicit intention of the book being translated. The first intended audience is typically readers in the original language.
This is opposed by producing a series for Amazon, where it is mostly clear that the intended audience is world wide, talking many languages (in particular if it is about such a famous topic). And I wouldn't be surprised if this fact does impact the production of a work.
I don’t think so. I think most writers are only fluent in a very small number of languages and they choose one of those languages to write in.