henias

5600x for gaming, 5900x for workstation uses

Definitely 5000 Series for a GPU like that as it's much faster for gaming, and even the 5600X would be fine to handle it.

If you can find the 5000 series available and you have (or are planning on getting) a compatible motherboard then I would recommend the 5000 series CPUs.  Decision between the _700X and _900X comes down to whether or not you need the extra cores.

I use headphone out from a Focusrite to studio monitors...works just fine, I am sure it would be better with RCA, but I have had issues getting cabling to work due to my own ineptitude and the problems of ordering online.

After setting up your custom fan curve, you need to enable auto fan speed and click the 'gear' logo on the left of the fan speed slider so there's a shade of colour around the fan speed slider. Otherwise it will use the factory fan curve

1. Set a custom fan curve.
 
2. No, dont touch the voltage. Not because it's dangerous, but it has literally 0 effect on overclocking. By pulling the slider, all it does is send more volts when clock speed is low. The upper limit of voltage is what you're already using now and you cant increase it by pulling the voltage slider.
 
As for whether you should touch the power limit, it depends on whether your card runs cool enough (below 75C is where I draw the line) under acceptable fan noise.
 
3. Voltage frequency curve lets you use the least amount of voltage for that frequency, hence saving power and reducing heat output and noise. You're still limited by the voltage upper limit and power limit.

78-83C is not an unusual jump for stress testing. As long as your peaks are below 85C (90C if you're aggressive), you're ok on Ryzen.
 
I have no idea what Jay was talking about. Thermal paste doesn't break down at 90C. If it did, none of us would have computers anymore. If you're concerned that you didn't apply enough thermal paste, go ahead and open it up to check. Otherwise, there's really no need to. 83C is what I would consider a good stopping point, not cause for alarm.

You've got nothing to worry about hitting those temperatures. As for checking the paste, It would be good testing to after running benchmarks to see its thermal performance, to check the thermal paste afterwards to ensure there was actually a good thermal paste spread, otherwise the CPU would be running artificially hot in the tests and not valid to compare because of a poor thermal paste application. This is likely what Jay was doing, its a good way to show transparency in testing.

He was most likely checking to see how the thermal paste spread under the pressure of the heat sink. Heat won't damage thermal paste unless you hold a blowtorch to it, and even then it would probably just dry up. 83 degrees is up there, but it wouldn't damage your CPU. I'd make sure there aren't any visible air bubble in the thermal paste and try remounting the cooler. Remember to mount it with a good amount of pressure, but stay within reasonable limits.

That isn't what a 24/7 overclock is, that's just what happens when you leave SpeedStep on or off. What you're referring to is a static vs dynamic overclock.

24/7 is also sometimes called daily driver. 

a 24/7 overclock describes an overclock setting that is stable all of the time.  Some people have overclocks that are stable for short periods so they can run benchmarks for high scores but then have separate overclock setups that are stable when running 24 hours a day / 7 days a week for absolutely everything the computer might do.  
 
So it doesn't pertain to anything specific to an overclock's settings but the fact that the overclock settings are 100% stable for absolutely everything they need to run. 

With a 1060 system, you'll draw about 200W at load. The lowest wattage good PSUs start at 400-450W, so that's what you should get. 
The efficiency is just the efficiency. It doesn't say anything about how good the PSU is. 
What's meant with a good PSU is good performance and good components, and often low noise.
The brand and efficiency doesn't really matter, as every company is equally capable of selling crap, and there are Titanium efficiency PSUs that are worse than bronze efficiency ones. 
 
Depending on what's available and the prices, Straight Power 11 450W, Whisper M 450W, RM550x 2018, RM550x or Formula 450W. If none are available, the Focus Plus Gold 550W, Focus Gold 450W, TX550M or Earthwatts Gold Pro 550W. For lower end ones, there's the Corsair Vengeance, CX450/M and Pure Power 10 400W.