The tagging and comments are preserved. Tabbles listens to the move, cut&paste, delete and rename operations, done inside Windows Explorer (now called File Manager): so when you move a file, the tagging of that file will be updated. Notes: By design, the Copy operation doesn't transfer the tagging to the new copy. You can copy/paste the tagging afterwards. If [...]
YES YES YES! Tabbles has a powerful users/groups management system, so you can control who can see/tag/untag what. You will need to have a database accessible from everyone in the group: you can use the Tabbles Cloud, setup your own database or we can setup one for you.
Yes it does. As long as you (and everyone sharing the Dropbox/OneDrive folder with) are synchronizing the folder(s) on your (their) PC, then you can tell Tabbles to "treat that folder on that PC as cloud folder". Check the setup instruction in the manual.