I agree 100% with your first statement, i launched mine out at Moab and it broke something every single time i went afterwards. Toyota housings are made out of 3/16 sheetmetal.
30/30 spline longs have been around forever, and they are probably just as strong or stronger than 30 spline 60 stuff but 35 spline 60 stuff costs about the same and is way stronger.
The 9.5 3rd has the same pinion as the mini 3rd and yes the ring gear has a bigger diameter but it is about half the thickness of the 8"...........and i'm really not convinced that 80 series frontends are worth fooling with, yes you get a bigger birf but it's still 30 spline, and have you ever seen a minitruck sized longfield with a broken birf? They pretty much always break at the splines so where's the upgrade? plus you have to deal with the weird knuckles, expensive highsteer and the scalloped hub flanges that you can't add dowels to.
Everyone worries about the extra weight of going to tons but i am convinced it's worth it for the extra strength and reliability. I've wheeled with the same two friends (both on tons) since about 2006 or so and there has never been an obstacle that i went up that they couldn't because of weight or clearance. Mainly i have spent a lot of time riding with them because my rig was on the trailer after i broke my toilet paper axles trying to follow them up stuff :****: