InfiniteClouds: I can REPLY to posts on Firefox... but when I try to make a new thread and I hit the button to post it just gets stuck on "Processing." I don't have the issue from my chromebook... wtf?
There are a number of reasons why that can happen however most of them are due to quoting related problems as Goodaltgamer eluded to above. You're saying this happens when trying to create a new thread however in which case you would not be using any quoting so that can't be the problem. Another thing that can cause this to happen is if your post is longer than the maximum limit of characters that can be put into a single post, whether a new post or a reply. That is solved by pasting the whole post into a text editor temporarily and splitting it up into smaller pieces and posting one chunk and submitting, then waiting 10 minutes or more and posting the second post, etc.
Another problem is if your web browser does not accept cookies on gog.com or if you block scripts or other subresources which are required for the website to operate properly using CookieMonster NoScript, RequestPolicyContinued or other similar addons. It's possible to use such addons but the proper exceptions must be added to each one to allow the proper traffic through for the website to function correctly.
That is not an exhaustive list of all problems that could be affecting you but it is a few known ones anyway that may or may not help troubleshoot and resolve the issue.
HTH