I've elaborated number 9. Please let me know if it's clear now.
Some of these methods do. For example, the tasks that power word vectors apply for many languages. https://fasttext.cc/docs/en/crawl-vectors.html
Masked Language Modeling has been applied to learn cross-lingual language models. Look into: https://arxiv.org/abs/1901.07291
Also, I always wondered, do those methods work universally on all languages? For example Chinese, Korean and Japanese, with different alphabets.