2. Are there any GPUs that actually have performed physical damage on a motherboard slot?
3. GPUs are already 2-wide by default, and some are 3-wide. 4-wide GPUs will have more support from the chassis. This seems like the simpler solution, especially since most people rarely have a 2nd add in card at all in their computers these days.
4. Perhaps the real issue is that PCIe extenders need to become a thing again, and GPUs can be placed in an anchored point elsewhere on the chassis. However, extending up to 4-wide GPUs seems more likely (because PCIe needs to get faster-and-faster. GPU-to-CPU communications is growing more and more important, so the PCIe 5 and PCIe 6 lanes are going to be harder and harder to extend out).
For now, its probably just an absurd look, but I'm not 100% convinced we have a real problem yet. For years, GPUs have drawn more power than the CPU/Motherboard combined, because GPUs perform most of the work in video games (ie: Matrix multiplication to move the list of vertices to the right location, and pixel-shaders to calculate the angle of light/shadows).