You may wait until we implemented a migration for that. As alternative you could delete the cached file in the content folder and redownload them with the new webgui, if you have the cloud rUID/auth cached already.
Which version are you using? We had a similar bug in the past which should be fixed. If not it would be nice if you could open an issue on our GitHub.
There shouldn’t be a json for those. This look like a bug related to the problem above.
No, it needs to stay there as it links the tag to the content. It also contains the cached cloud rUID/auth
This central place are the jsons within the content folder.