There's not necessarily one next hop. If you can stuff more packets than standard out to your upstream, and the upstream delivers the packets over multiple interfaces, it can pad the packets out to the standard length, and you get > 100% utilization.

I understand the original purpose of the minimum packet length (needed for reliable collision detection), but I don't think it's really necessary for gigE, where I believe full duplex, point to point connections are mandated. I also don't think the minimum size would be sufficient to guarantee collision detection in a hypothetical shared medium at the allowed bitrate and distances. Frame to frame delay on the other hand, seems like it would still be useful , although maybe it could be tuned.

Good answer +1, I was sort of thinking about this but I didnt have the knowledge.

I've no idea. That's why I'm asking. I guess internal use, yes, i.e.: for high-throughput local network infrastructure. I guess just going to 10GbE or fibre would be a cheaper method.