search for the holy grail continues
I don't have the answer, however I've got a few comments.
1 You need a viewfinder. And not a sticky up clip on one. Trying to get a shot with the sun on a screen is hopeless. Electronic viewfinders, ie mirrorless, can be laggy, mirrors work at the speed of light and are mature technology. Failing a mirror a parallax prone viewfinder is fine.
2 It's got to write to it's medium fast. Partly you need a fast card, mostly you need a fast camera. I have a 'Leica' (ie a panasonic, met a good salesman...) D LUX 3 and it's slow almost to the point of uselessness. In a lot of other respects it's a lovely camera and I use it mainly because it's small. However I miss loads of shots because it's slow and has no viewfinder - squinting at a screen in adverse light with the wrong specs on just doesn't do it.
3 Buy the lens, not the camera. Well ok, the camera has to be alright - see what this guy has to say. I have a (relatively) cheap Nikon DSLR. Nice camera, fast, but I really don't like the lens. The 'Leica' has a Leica lens and, given sensor size, price and size I think it's a marvellous lens. The Nikon lens just doesn't seem sharp to me. It may be product variability - read this - but whatever the cause, you need to be looking very closely at the specific lens you're buying. This implies you're buying in meatspace, not on Amazon or somesuch.
4 Auto focus. You need to be able to operate the camera without auto focus. My Nikon does camera says no when auto focus fails, which is super annoying. Ok, use manual focus. Wind the focus ring right out, we're focussing at ∞, off we go. Sadly not, the dammned thing is focussing beyond infinity. Super annoying. Pay attention to the lens.
5 RAW files can save your bacon, if the auto exposure gets it wrong, you've got plus or minus 4 stops to play with.
If you're looking for something to takes snaps as you schlep round a trade fair, none of this matters too much, but then you would just use your mobile, no? The one camera I had that nearly fits your criteria was a point and shoot film Pentax from 30 years ago. No zoom, not beer proof, but fixed focus, everything from 4 feet to ∞ in focus, fast, although you did have to wind the film on yourself!
Good hunting, I'll look at the answer with interest.