I am suggesting the following for localizing entries:
Instead of using ‘default’ rename it to English and make option to choose default language in locales settings.
Return back the old translation drop-down instead of hiding and showing translation in entry page, its not practical when you have many languages and confusing the users.
The new language UI was introduced because of the feedback of people who do translation on a daily basis. they don’t want to switch back and forth while translating content. But you can’t please everyone I guess
1- keeping it default then i need to put extra code in client side to set the default language when calling api and sometimes i need to use other languages rather than English and i need to use language code instead of checking the language name.
2- you are right but they can use the copy button , but maybe we would need different approach like Directus do.