Ethanol is alcohol, methanol is a by product of fermentation. It’s present in small amounts in beer and wine. Unfortunately if the fermentation goes awry, it’s present in high enough concentration that it will kill., its more of an issue in fruit fermentation though. And a huge problem in places like Bali, where Aussies love to holiday
Yep sanitation is another issue. Gotta have clean pipes and barrels. You can get bacteria that will make you very sick, and even be fatal too. The main one in poor production, esp in wort is botulism. And that’s related to pH parameters. Boiling won’t kill botulism spores, unless boiled for hours and hours. So it has to be controlled with pH.
One spore will kill you.