Your post is the most well thought out and logical post I HAVE SEEN ON ANY QUESTION STRING!!! I have seen many on other question lines. I want to encourage you to form a new question and include your post under it. Please post something here to tell me what question to look for. Maybe your question could be " WHY CAN'T I CONTROL MY FIREFOX"

I am not sure you got my reply, for some reason your post disappeared when I posted my reply. Your post is well thought out and logical. I have seen many complaints about firefox on many different question strings. Your post deserves a wider audience. I want to encourage you to start a new question line and use your post under the question. I would suggest " Why can't I control my firefox - how can I stop automatic updates ? "

Be sure to post something here to let me know the question to look for.

In this case the download extensions stopped working because YouTube made changes and in such a case it won't help not to update Firefox because the extension itself is broken and needs an update to catch up.

Matty, you do know that Chrome updates just as often, if not more than Firefox? And this case was not Firefox updating that broke your extension but youtube?