But I'm interested in the publication date (sync) of the new translations. I think the new translation must syncronize with the older published post. :/ (It's possible?)
You can play with the "published date" synchronization in Polylang settings to control that.
Also a more easy way to find the posts in other langs, like the selector (dropdown)in the tags/categories.
You can play with the languages menu in the admin bar on top of your screen. I don't use the same interface as WordPress for categories because the language filter is persistant accross pages (and also active in some places where there is no category filters such as menus)