I haven't read anything but the last page. B12 is available in Ca. Good stuff. Gumout? I haven't used it for decades since I figured out that it swells up and ruins rubber. Rubber is an important element of our carbs! I really do think such carb cleaners have something to do with carb diaphragms biting it. Normally they last for decades. B12 might swell rubber too but I have never been tempted to put it on or in assembled carbs.
I read on the internet that Amorall is no good. I have used it for decades on my own bikes and have never seen any trouble for it.