Whiteshark, have you had any playtest results with your revised system?
My group likes the GMG's Alternative Scores system and I think yours takes it a fair step further. I appreciate how well you've thought this out with your math builds.
I think I'm most concerned about the Sneak Attack damage changes you added in your latest revision though. There was a lot to go through above, so I apologize if I misunderstood, but it looks like you identified Sneak Attack to be considered over-tuned even without the alternate attribute system?
So I would think nerfing Sneak Attack should be considered separate from a revised alternate attribute system.