To get right to OCing the CPU without worrying about DRAM, get to the Extreme Tweaker tab and set AI Tuner to Manual. Leave BCLK frequency (Base Clock setting) at its default values, set the multiplier to 45. Enter the Digi+ Power Control menu within the Extreme Tweaker tab, set CPU Current Capability to 120%. You can raise this at a later time, but I don't recommend going above 130% for the sake of your VRM temps. While in the DIGI+ Power Control menu, set CPU Load Line Calibration to 5. Now save your settings and test your OC.
A rundown of what you've just done:
1) CPU Base Clock: This is the speed at which the CPU runs internally at the lowest level. This is mainly used for fine tuning the overclock and isn't very useful until you hit the limit of the multiplier.
2) Multiplier: It amplifies the internal speed of the CPU. Multiply Base Clock by the Multiplier to get the targeted CPU speed. For example: 100MHz*47=4700MHz.
3) CPU Current Cabability: Allows for more current draw through the VRMs.
4) CPU Load Line Calibration: Sets the point at which the CPU should run at a lower voltage (regulated by MOSFET load and temperatures). A higher setting will allow for more stable voltages but will result in higher MOSFET temperatures. As this board has excellent MOSFET cooling (that massive assembly that wraps around the left and top of the socket), you should be fine at up to 130%. 140% may be pushing it, but I doubt it would destroy the board. Your MOSFETs are rated for 130C, but I personally don't like to see them go above 110C. In all honesty, if the OC is stable then you should be fine.
Liquid-X :
DDR4 can overclock to 3000 Mhz, but in bios it shows as 2800 Mhz because thats what i set to, but I'm not sure if it means that it has been overclocked to that speed
It's trying to get to 3000MHz but something must be holding it back. Try adding the lowest amount of voltage the board will allow onto the DRAM. Example: If it goes by increments of 0.001V, apply 0.001V more. This may allow your DRAM to reach its advertised speeds. Continue increasing voltage by small increments until either the DRAM heats up or it achieves 3000MHz.
Also, I'll be offline for a few hours. I'll be available later today, likely after dinner.