Other people's cooking makes me feel sick

Talking over food? I don't get this, do I have to chop veg in silence?

Your examples are valid. Sounds bonkers but I have to work hard at not overthinking stuff otherwise I would go OCD Doolaley re hygiene e.g I've yet again ravaged my hands because had an hospital appointment and between sanitation gels and hand washes have got multiple blisters because I over obsess.
I once worked away from home (in the middle of nowhere) and was completely dependent on canteen food. I swear one Server would drip sweat onto the food. I think I lived off fruit, crisps and chocolate - because packaged sandwiches were made on-site!

I'm funny about people's food hygiene too, mainly washing hands, cutlery / plates /pans etc. Mainly because I've noticed people absolutely do not do these things properly and it's utterly gross.

Talking over food they're making doesn't bother me, unless they're actually spitting. Ditto being sweaty, unless they're dripping.

As someone who does not have these type of concerns at all, this sounds very hard to live with. Eating with friends and family has always been a really normal and important part of life. This fear that you (and others on this thread) have lessens the joy in life. However, I don't know how to advise you to learn to reduce it, I'm sorry. Maybe do some reading on excessive worry about hygiene and see if you can find advice?

Cats on the chopping board.......shudder....yanbu

Poor food hygiene is gross, but if it goes beyond that and is affecting your life enough to post about it, maybe therapy would help. If you think you might have OCD, seeking a diagnosis might also help you.

those things you mention are grim and i would be making it a bit of a teaching moment.
my past workplace was one where baked goods/foods were often dropped off for staff, and 100% without a doubt staff only ate foods by people we knew closely or knew they were good cooks from community pot lucks etc.

I have the talking over food issue as well I threw a subway sandwich away because the woman was talking over it it’s disgusting and rude

I get you. i dread home made stuff too like cakes,buns,jams,fudge etc and no matter how lovely the thought as a treat etc it goes in the bin, I just can't.

Your post doesn't sound awful to me - I am obsessed with food hygiene and it's caused me a lot of stress over the years - I think in my case it's paired with health anxiety and maybe OCD as well. The licking fingers example properly grosses me out. I wonder if you could arrange to do things that don't involve other people cooking for you (even if you have to say "I've got this weird thing at the moment where I don't want to eat food cooked by other people; I'm working on it" - although I accept that might be hard to do for people who aren't close to you). In the long run, it's probably worth some therapy.

Had to politely remove a long curling grey hair out of my mouth last time I ate someone's home-cooked food.

To be fair the things you are describing sound fair as they are all unhygienic practices by those cooks. I suppose the real question is can you eat food prepared by others when you dont see them cooking? In restaurants for example and houses where you aren't watching them

I feel exactly the same way about food preparation. I feel very scared about the hygiene of other people when cooking. I have OCD. Themes like this don’t just revolve around a fear of getting sick, the actual root fear could come from anything - even just the fear of the uncomfortable feeling that something hasn’t been done “right” is a subtype of OCD. Fears of contamination can stem from anything: the stereotype of someone with a contamination fear is that they would compulsively clean, however, for many even the thought of cleaning triggers the anxiety because they don’t want to have to touch or be near the thing they perceive to be contaminated.

I’d suggest looking into it a little bit more, because it can be hard to understand fully, but you’re not alone.