Firefox: window decoration and snippets

I’ve been looking back to Firefox recently, after the latest release of Chrome showing some weird behavior. I am still not sure I want to change my browser, at least not until I am sure I can set it up to my liking. I have not used it for years and the interface have changes quite a bit, successfully mimicking Chrome. Anyway, upon start there were two things that I wanted to change immediately: the window decoration and the so called snippets.

To make Firefox use the GTK3 window decoration, instead of the window manager, go to “Customize” and uncheck “Title bar”:

So far so good, however upon start I would receive constantly News / updates from Firefox and Mozilla. To remove this, go to “Preferences” and unselect “Snippets”:

So far so good.
I am looking for a way to change the scrollbars now…