Alright! Now to tackle them bugs!

EsalRider's list:
Script tries to subscribe to pool #0 if no pool is in the old tracker variable. Converting notification shows up but the process never finishes. Error "unable to load resource" appears in the console (e621.net/pool/show.json?id=0). (had to manually delete the variable instead)
Added a check that makes sure that the last pool ID exists and is not 0. It did that because I forgot that when you clicked "Stop Reading" id stored 0 instead of just removing the tracker. *derp*

On a related note, the userbar appears on .json pages when viewed directly in the browser. And on error pages like the one for no pool with id 0 (XD). Not that important, though.
Added an exclusion at the script header. Since my browser opens JSON files on notepad I didn't really thought that much about viewing them there.

Once again, the navigation guides don't show up when clicking the "read" button on a post's page. And the hotkeys aren't responding then as well (unless refreshing / going to another page).
I know that. I've been trying to get that darn pesky bug, because it does work sometimes :I

Edit: I'll try to fix that one too, I don't know what causes it :/

To the Bug, I will find you. And I will kill you. *hangs phone*

</Edit>

When clicking the Wiki button to change the highlighted text to a wiki link, the edit box will show up, completely empty. But no matter what you write into the fields, the highlighted word will be simply surrounded with double square brackets, and custom title won't be added.
Fixed. It was an old piece of code that I overlooked when I did the "so many improvements". It was also at the Link button.

You forgot to change the script download URLs in the "How to install" section.
Done. Again, good catch!

The "Get source" bug reversed itself. Now it does nothing on posts with at least one source.
Fixed again

PheagleAdler's (single item) list:
Can't get to my user page using the orange link in the top right. Keeps linking to 'https://e621.net/user/show/undefined'[/s]
Fixed and added a check that finds your details (username, id and level. Not the other details) and stores them. Going to the static page ( » ) will trigger the action regardless if it has been saved alreadyOk, Those were all of them (as of now, that is :) ). Current version should be 2.874