One option would be to have a camera underneath, then you could actually use the screen as an evf.
Tablet-photography sucks.
I had considered that in one of my
rants posts above. The distance from the motherboard to the case exterior is at least adequate there. However, a camera feature is pretty large in all 3 dimensions - like an 6-8mm cube's worth of space. That would mean a square notch or hole through the battery, a more complex battery configuration and a slightly lower battery capacity. All of that is then if a camera on the bottom of the unit is acceptable AND if other features on the motherboard could be shrunk/moved/etc. It would have to be somewhere on the board where the SD slots, CPU SoC module, ports, stylus, etc are not - which pretty much means it would be somewhere on the other side of the case from the right nub.
It would be useless for video conferencing or video chat. It would be prone to scratches - the lens would be on the surface meant to sit on other objects. It would by necessity of costs be a truly crappy low resolution thing. It would decrease battery size and thus charge capacity. It would require redesign of battery, motherboard and changing the position of many components. But - in that position - on the back/bottom of the case under the right nub/game controls is likely enough physical volume, orientation and distance from the motherboard to a case edge.
And you're right on your second point too.