You might want to try disabling or removing the LinkSwift extension. You can do that on the Add-ons page:

orange Firefox button (or Tools menu) > Add-ons

In the left column, click Extensions

Your system information also shows that you have a user.js file in your settings folder. This file is read every time Firefox starts and can override your own settings. To investigate this, check out the steps in this article: How to fix preferences that won't save.

Any progress?

There have been a rash of reports about fake update messages over the last 3 or 4 weeks. Unfortunately, too many users didn't recognize those as fake messages and made things worse by installing the fake update.