Once figured out I'm now able to access my remote torrent clients (deluge) web UI through the add-on, however it refuses to grab torrent files; EVERYTIME I get a "403 failed to get torrent" error (don't recall exact wording).

Does work with rutorrent and htaccess based access. However, the combination of labels and folders is impossible - it's either one or the other.
Configuration also isn't very intuitive, could use some clearer language or documentation.
Finally adding more than a 2-3 click add to torrent, why not make it a handler when downloading files? If it's there, it definitely doesn't work here.

The point of this is to add multiple torrents fairly conviently, I find this plugin barely adds any value compared to going back and forth with the ruttorent tab.

Looks good, but doesn't work for me, always get 404. I know the path and auth are right, clicking the icon even brings me to the right page, but adding magnet links doesn't work. (I think because it's under a /path, due to being behind a reverse proxy) I've used other things that work with the API, so the reverse proxy is okay, I think your extension just doesn't like example.com/rtorrent as my path. Any way I can get a hotfix for this? Another potential problem is that your extension may be doing DNS lookup for the path with its own DNS server. (As my path resolves differently from my internal DNS server than it does for external servers)