I liked No Script on Firefox. I'm not sure if Safari has something similar or if it's even needed, because typically when I go to a new page, I just turn on individual scripts until I get functionality out of the page. Safari is so nice in this regard (low cpu usage), I may not go back to Firefox.I stopped all my Add-ons recently and started seeing some stability. They're labeling most of their Add-ons as Legacy with the new transition with the exception of the few already ahead of the curve and updated their code.
Or maybe the answer would be to go back to Firefox and turn off most of the add-ons. I like the ones that warn of fake pages.