Your prime95 temps are far too high, that's what's causing the thermal shutdown. If I had to guess what your number one reason for failing, it would be due to thermal reasons. As you increase temperature, higher voltages are necessary for stability. Unfortunately, higher voltage produces more heat, and the vicious cycle continues. Even although the die is spec to 100C, you can start seeing instability in the high 80's because you can't account for spikes that the thermal sensor isn't quick enough to notice. Although it may reduce your temperatures may drop a little, beefing up the fan will do little to adding stability; you most likely need to try reapplying thermal paste or reseating it. I hesitate to say that it's inadequate because many people have gotten higher frequencies on air, but mileage always varies. I've tested chips on my rig that don't break 4ghz under any reasonable amount of voltage on my custom water loop. Just because somebody got x frequency on the 930, doesn't guarantee yours always will. In the end, Intel is just trying to make money, as long as it passes the spec, they're gonna sell it. They aren't obligated to sell you a part that goes 4ghz if you're only paying for 2.8

Other than that, your DDR voltage seems a bit low as well, but if it passes memtest, then it's most likely not the cause. That doesn't mean your memory subsystem is broken (ie your cache, imc could be failing). But most of what you've said point towards thermal instability.