Funnily there is also the word "Mitgift" (Dowry) that has nothing to do with poison at all and is closer to the english "gift".

Same root though. In Dutch it wasn't differentiated until recently so the same word has vastly different meanings between Afrikaans and Dutch. https://en.m.wiktionary.org/wiki/gifte#Middle_Low_German

Original meaning seems to be something that was given. So a snake would gift you Poison just like snot nosed brats would gift you a cold during Thanksgiving dinner.

Same meaning as dose in that sense. https://en.m.wiktionary.org/wiki/dosis#Latin

I don't think it matters in most contexts. When people are casually talking about it, venomous and poisonous are both stand-ins for "it has venom." They're not telling other people, "actually, don't eat spiders." I was just joking about the classic pedant line about spiders.

But it does make a difference on paper. I'm curious how you would express this in German: A black widow is venomous and in theory a healthy human can eat a dead black widow with no ill effects.