LiquidTech

We can't tell you how long your CPU is going to last.
 
The average life expectancy of your typical CPU is at least 8 years. It will still physically be usable, but most users ditch their CPU looong before it is completely unusable.
 
1.52V seems pretty high, I would dial back the overclock. That's not exactly the safest voltage around...

It will slowly degrade, but whether this becomes an issue for you in one or five years is hard to say - depends on how heavily you use it. You could try running it like that for as long as it remains stable. If you start encountering errors, I would just drop the overclock and voltage a bit.

Nice OC, what cooler are you using?
PS: Nice background picture.

if they can't give a replacement, they should give you an equivalent of equal or greater value, or the full retail price you paid for it, if neither ask for a response for the RMA department manager and depending on country threaten to use consumer protection laws against them.

Great!
So just enjoy the 1080 and know you won't be tapping on its full potential until you upgrade your CPU. I prefer the 7700k.

Because, quite frankly, Kaby is a refined, and iGPu update, of Skylake. The only advantage a 6+ core Kaby could bring over Skylake-X is a slight overclocking increase. With X99/X299 being targeted partially as a professional platform, the psuedo-improvements wouldn't be overly welcome as an update to Skylake-X.
Quite frankly, Skylake-X should have never existed, or should have been the lower end SKUs of X299. Kaby-X should have been the higher core count parts, leveraging its better power efficiency to bring up stock clocks, even by a small amount.
 
Kaby-X is a stupid product. It has zero advantages over Kaby Lake, and no real purpose that can ever actually justify it being on X299.

For the millionth fucking time. The thermal paste that Intel uses is called Dow Corning TC-1996, EVGA uses the same paste and Intel uses the same paste on Skylake and Devils Canynon and most of those CPUs don't have thermal issues. Which shows you that the thermal paste itself is fine, but the application method sucks. You always keep saying that Intel should solder their CPUs, but for the millionth time I am telling you that Intel can't do that:
http://overclocking.guide/the-truth-about-cpu-soldering/
If you think that the article is false, send an application form to Intel. They could definitely use your "expertise".
Now can you please stop shitting on Intel?

Well, options seems to be:
 
1. Get a better cooler
2. Lower your OC.
3. Get 2k rpm fans and slightly lower your OC.
4. Revise option 1.

Look for the socket number. Both of them are socket 1151 and the motherboard states that it supports 6th and 7th generation core processors.

RMA it if you can. If you can't then keep using it and don't mess with the pins, as trying to bend them back will probs make it worse. 

Slightly off topic: You didn't mention about the PSU you're using?
And also it's 4.2GHz not 4.2MHz
 
Back to topic, as others mentioned above, try some stress tests for a few hours (if you have the time)

Run something like Prime95, OCCT Linpak or AIDA64 for a few hours to make sure its stable.

seems so, if prime95 isn't playing ball try AIDA64, but usually instability results in outright crashes although not always, do be careful though, anything past 4.3GHz is going to need BCLK adjustments, so maybe brush up on that if you wanna go higher/ 

Looks good.
CPU frequency will drop on idle. Perfectly normal.