Hi,
You can already remove the current page from Pocket if it's in Pocket. Just right-click anywhere on the open page and choose Pickpocket > Remove Page from Pocket. (This usually works. But if the URL of the current tab is at all different from the URL of the Pocket item, the context menu won't show that command.)
To change tags for the Pocket item corresponding to the current page, open Pickpocket and click the Add button (the big plus sign). Enter the new tag(s) and click Save. This will also have the effect of re-adding the page to your Pocket queue, if it was in the archive.
You may also want to take a look at the option "Archive each opened link". If you enable this option, your Pocket links will be automatically moved from the queue to the archive when you open them using Pickpocket, thus hiding them from Pickpocket's default listing.
Chul