Make tag additions/removals less chaotic in the viewer
When opening a tag folder or the Untagged folder, create a list of the files at time of open, use this as the feed to the image viewer so that removing or adding tags does not make the current image disappear immediately. When exiting single image view back to the folder contents, THEN re-evaluate the contents of the folder, and display changes. This would allow for multiple tags to be added while viewing the Untagged folder or when recategorizing an image in the wrong tag folder.
Along this line, bulk rename ("mypic 001, etc) Would be nice. Also, how about a folder called working (or whatever). Move photos to this folder and bulk rename or retag them, then move to appropriate folder. Any variation on this ( such as bulk name/tag on selected files ok.