Major, I'm not sure why your experience is so much different than mine. Do you have a wider mill gap, or a different knurl pattern? I'm using the barley crusher and have had issues pretty much since day one with runoff with a 0.025 mill gap. It would never get totally stuck, but get extremely slow with standing wort still visible in the tun. I found the system to be very sensitive to how I vourlaufed, I couldn't pour the wort back on top slow enough. Since I started conditioning, vourlauf and runoff has been a non-issue.
As for good for the grain mill, I agree that this last one was probably a bit too much based on the amount of force I needed to turn the mill over, and I'll likely back off on the water for future batches. I haven't seen any rust yet (roughly 12 batches conditioned in 5 months), but the mill does not have stainless rollers so it is a possibility. Could be that the flour keeps the rollers from staying wet, or the fact that it's only exposed for 10 minutes a week? The grain isn't dripping with water, it just gets a bit soft. I'll post an update if the situation changes.
As for rice hulls, the downside for me is the cost. 1/2 lb adds roughly a dollar a beer, so over the year that's another batch I could have brewed, which is important when you're on a budget. I've only used them once, so I'm no expert, maybe you can get away with less. They can absorb some wort if not pre soaked, I haven't evaluated if they absorb any additional wort when they hit the mash.