Older Sony mirrorless have most of what you're looking for. I got a Sony a6000 for 350€ and it has auto iso with cap (but not auto shutter speed with cap), pretty good custom controls although I wish for more, great size, great autofocus. It does lack great low light performance, I also struggle with that, but maybe a full frame would be better for that.

You may want to try it out for cheaper and then buy lenses, and once you're committed to the ecosystem buy a nicer more recent Sony.

Nope there's a feature that lets you download the screenshot to your phone wirelessly

8mm film in a cinemascope movie?

Ah nice. I'd have assumed it was replaceable with screws or something, not pop out and replace. This idea of having a phone and two batteries is really interesting and is definitely raising the possibilities I buy a fp5.

Edit: would be even cooler if you could charge the second battery independently.

Is the fairphone's battery as easily replaceable as old phones were? I'd think that would make waterproofing really difficult

About mattresses. I hike and backpack and I can attest that sleeping on the ground (meaning earth and grass) with a tent and a pad is fantastic. But you can't really do that in your house. I'd love to, cheaper, less noise, less hassle, but the floor is hard. Even with a big air mattress I find it extremely uncomfortable. I'd love to try a hammock, but without an expensive stand you can't comfortably set it up in a house. Advice?