It's obviously the EVGA Kingpin due to the high power limit. You have been around the block. Seems like you already know this and are just posting for attention.
Obviously a 10900k would be best, but the 10700k will be almost as good. That is what I have. I couldn't find a 10900k in stock. Even with PCIE 3.0, these chips are faster than anything AMD has for gaming.
The z490 boards support PCIe 4.0, but the CPU's don't. It is safe to get a 10700k, then replace with a 4.0 supported CPU when they come out, as it will slot into the z490 board.
I built a system for my GF using this chip and cannot get over 4.8. Seems pretty normal. If you bought it from amazon you can return and try for a better chip.
Depends on your financial situation. I loved my 1080ti, but the 2080ti is definitely faster! My two fan evga card is super loud though. Get a least a 3 fan or water cooled 2080ti.