I understand what you mean, when I was fixing the other issues you brought up I also thought there was an admin option for file handling!
1. What do you mean here? A page that lists all file uploads, and you can update/delete them for example?
2. I don't think this is feasible because the path is likely to be dynamic, i.e. based on $_SERVER['DOCUMENT_ROOT']. With an admin option you'd need to add '/var/www/sitename' or something, which isn't flexible if you switch servers or make other server changes.
3. Yes, this makes sense. I also realised there was a potential issue if you switch to using file storage but don't migrate the DB yet. You'd have some files in the DB and some on disk, but there is only one button in the admin, to move all files to disk. If you decide you want to use the DB you have to move the DB files to disk, then move back to the database, then remove the QA_BLOBS_DIRECTORY variable.