Hi, bazotto,
I’d never come across the answer to 30ac before. As already noted by Meursault and others, the clue needs to be corrected from “chief fluent” to “chi affluent”. In this case, “chi” refers to the Chinese life force, which is now more usually transliterated as “qi”. The rest should be available to you from crossing answers.
In 20dn, the final letter is cryptically indicated by “Spain”.