I miss a shortcut to move/copy selected notes into a specific tag, while using an autocomplete search to find said tag.
I know this can be made manually by adding the tag at the bottom of any note, but this would let us do it without manually moving the cursor and/or in multiple notes at once.
You can multi select notes in note list (⌘+Click or shift+Click on Mac, or on iOS/iPad by hold and drag while tapping on more notes, finger gymnastics), then drag and drop the selected notes into any tag in the tag list.
This will add this tag at the end of all your selected notes, without updating modified date 
Yes, I know.
However, the idea would be to be able to file/sort notes from the keyboard alone and without needing the desired tag to be visible on the screen (the desired tag could be below the scroll fold or collapsed).