> When viewing tagged files, they show as if they are a gallery. Is there a way to actually delete the file from there [..]
No, in a gallery, the delete functions only remove the thumbnail from that gallery.
> [..] or do I have to copy to a folder and kill them at that point?
Well, you could move them to a folder and delete them there. But what I usually do is when I'm done tagging, I use Edit | Select by | Tagged to select all the tagged files and then I press Del to delete them.
(or if I have tagged files from multiple folders, I first go to their common parent folder and turn on 'Include Child Folders', so that all tagged files will be in the thumbnail listing. Then I can select and delete them in one go.)