I know that one's Google Drive data can be restored after being permanently deleted (on the user side), for a month or two following that. Obviously, Google doesn't commit to a specific time period with which this can be done, but it means that Google doesn't delete your data immediately. They probably follow a method that is most efficient for them (e.g. ...
I don't think that is possible under the current state of development of the app, since the "Collaborate" setting is global.
If you really needed to, you could share the password to the Google account, with your collaborators (creating a shared 2FA key would make this system smoother).
In your Google Photos album, click on the three vertical dots on the top-right, to pull up the menu for the album.
Click on "Edit album".
When you are displaying the correct place in the album, click on the TT icon, to add narrative text within the album.
This can be a fun way to tell a story to viewers of the album.
I've written a desktop app (http://jiotty-photos-uploader.yudichev.net) that scans a folder, including all subfolders, for photos and videos, and uploads them to your Google Photos gallery arranging into albums according to the directory structure. As Google Photos does not support nested albums, it will name albums like "Level1: Level2: Level3" if ...