I just went through this with a 56 with the same requirements. Dealer wouldn't sell me anything more than a "grass blade" as my cutter wasn't "rated" for anymore more. I acquired the tri-blade deal and it works fantastic.
The concern supposedly comes from the lack of solid shaft in the cheaper...
The only time I've experienced enough sway to bother me was when the trailer was empty. Oddly enough, both my trailers were purchased ~850 miles away and came home empty.
I've always towed with 3/4 tons or a (now) 1 ton though!
You're on the right track. You could do CAT6 but should have lightning arrestors at each end.
3/4" conduit should be fine but the pre-terminated end would be the deciding factor.
I think next time I see a carbide chain in the saw shop, I'll grab one to try.
I've been thinking of picking up another saw for bucking larger trees and just need an excuse anyways.... ;)
Since we're on the topic - what chains do you folks like using?
I replaced one of my abused chains with a Husqvarna X cut (that was all the hardware store had) and was pretty impressed with how well it's held up since the change. It's only needed to be tightened once and I've put it through ~3...
I usually touch mine up when refuelling so that I can catch an issue before it becomes a bigger one. I have no experience with the electric sharpeners, but I have 3 saws and probably 15-20 chains. I don't cut wood for heat (yet) - just acreage management between 2 properties. My family benefits...