I have merged your other ticket into this one. Please do not post multiple seperate tickets for the same issue.

But when I go via a menu item (with a dedicated category id) to write a new article then it doesnt work. I think because there is not yet a catid, because the article is not yet submitted so not yet in the database.

The catid cannot be used until a catid has been assigned, either in an existing article or when selecting the category for a new article.

Dynamic variables for the File Directory Path are not recommended for this reason.

So which key I can use instead? Or (and then I come back to my first question) is there another way to preset the image path per profile via an override?

It is possible to override the image path using a Joomla event, bit it would require you to develop a custom plugin for this.

so which keys I can use for the query option field? Is there a list of key names I can use?

I can be anything that is passed in the url query or the page request.

For variables in the File Directory Path, see - https://www.joomlacontenteditor.net/support/tutorials/editor/setting-the-file-directory-path