Hello mich. As I have mentioned before, I am a former AVG Free user who will never go back, and I do not think you are being paranoid. Please tell me that you did not click the blue "Fix Performance" button in the middle of the AVG UI and allow it to install a "free trial" of AVG PC TuneUp??? That might possibly be related to the fact that neither the Firefox updater nor online installers seem to work for you.
If you want to uninstall AVG Free, you should first go to Advanced Settings and turn off AVG Self Protection. Otherwise you might have to download their removal tool, which (like all AVG software) may or may not work right.
If you want to continue using AVG products, then you should sign up at AVG Support Community.