Oh I know, and believe me im very critical of what Sony is doing, but im getting kind of annoyed when people out there make stuff up. It gets hard to find the truth.
Like I said, i have to have some hope that things are going to be better for the sake of my lenses, had Nikon or Canon a comparable device on the marked I would be all over it.
I'm hearing rumors that Nikon has a full frame mirrorless coming... "soon." Very interested to see the likes of Nikon and Canon enter the market with some competitive camera bodies.
I don't do much video shooting personally, so I've never experienced overheating issues with the Sony bodies I've used (a7r ii, a6500, RX100) even shooting thousands of photos in burst modes over a short amount of time in hot weather and direct sunlight and shooting the occasional short 24fps/4K or 120 fps/720p video clip.
You can't take a picture without IBIS, Eye focus, an EVF, face recognition and something else that I either don't have on my dslr or turned off on my mirrorless?
You can take "a picture" with any camera. All of the tech you listed off enables you to more easily and more quickly take photos in a wide variety of specific scenarios. These aren't just unnecessary luxuries or gimmicks any more than a digital sensor being able to record data to a memory card is an unnecessary luxury in the face of film rolls and mechanical cameras.
For a given scene, what is the correct exposure?
Obviously the real answer is "whatever exposure gives you the look you're going for." I think it's generally considered that when you're exposure meter is at 0 or in the center, you are "correctly" exposing for whatever metering mode you're in. Another definition might be a photo in which there is no highlight or shadow clipping. Again, none of this matters since creativity is king.
I usually shoot in automatic aperture and shutter and set all the rest to my liking and the ring is for manual focussing. But it's the ISO that needs constant adjustments yes, maybe I do need to map it to the button. I don't always find the auto ISO trustworthy, but you can limit the maximum range? Complete manual mode is still a bit complex for me, but when I have the time to create a good shot I usually fiddle with it to test things out. Like I said I'm not a pro, I just want to get better at taking nice shots on holiday or in the neighbourhood.
I would recommend mapping it to a button, or at the very least setting it to auto. It's very flexible. You can sit a minimum ISO and a maximum ISO and it will obey those limits even if it means it's over/under exposing for your given metering mode. When shooting aperture priority or full automatic, you can also set a minimum shutter speed. In those modes, the camera will first try to lower the shutter speed before increasing ISO, but if you set your minimum shutter speed in the auto ISO settings to, say, 1/60, it will never reduce your shutter speed lower than that and will give priority to auto ISO adjustments. Even in that mode, if it's already lowered the shutter speed to 1/60, and it's already at the maximum ISO you set, it will just underexpose the image. Very handy.
On my RX100V, I have the ISO range set from 80 (extended) to 800. I usually shoot in manual or shutter priority, so I don't really bother with the minimum shutter speed setting, but I think it's at 1/60.