1.4V is doable, but you have to let the CPU temps go even lower than it does now (target 65C) (the higher the voltage, the lower the safe temperature).
1.4V will be the absolute max for ambient cooling with your board. The thing is, Skylake and Kaby Lake CPUs top at 1.45V for ambient cooling, but I dont know whether the software voltage readings of your motherboard is accurate or not. You need a multimeter to tell.
Yes temps will drop significantly, though not so much the noise level.
The lower the temperature (CPU and VRMs on the motherboard), the more stable it will be even when the settings are the same.
That's it. other measures hurt performance and ruins the point of increasing stability without dropping clocks.
I'm not so hardcore when it comes to stress test and I only do 5 minutes per try. I just bump the last stable voltage by another 0.05V to ensure stability....
Again, safe temps depends on voltage. 85C is fine for 1.3V, 75C is fine for 1.35V, 65C is good for 1.4V. It's fine if you ditch stress test and use voltages just enough to do things you do, say run games even if it crashes stress tests, but you run the risk of a crash.
