Then flip the Windows button around to the other side.

How do you flip a capacitive hardware button anywhere? If I rotate the Surface, then my other and will be touching the button.

If you're holding it in the corner, the aspect ratio isn't going to make much of a difference. It's going to be heavy no matter what. So you are holding it wrong.

That's my whole point. A 16:9 device is awkward to hold, especially if the device is heavy like the Surface is. Perhaps MS will be able to do something in software to compensate for that sensitivity.

In my use cases, my hands aren't needed to support the majority of the weight, whether it's with one hand or with two hands. I either have it on a table or resting on my belly if I'm lounging on the sofa.

That's a pretty narrow use case. As a mobile device, I very rarely reach for the Surface because it's not nearly as convenient as other tablet options. And a few times I have reached for it, I have regretted later because the batter had run dead. If you leave it in standby for more than a few days without it being on the charger, it'll be dead. Never have that problem with the iPad, but on more than one occasion I've arrived with my Surface only to find it completely drained and unusable.