The latest Intel 7th generation core i processors and 270 boards can be made to work and will run macOS, but the process is not as easy as with the 6 generation as at this point in time Apple has not publicly released hardware that shares this latest platform. There are at present some temporary workarounds. Your Intel Ethernet is supported port is supported.
Many past model Asus boards have featured compatible wifi and BT, however I cannot find what hardware that your board is using. it is possible to change this over for compatible hardware or remove it all together if you do not use it. I don't think that the audio will work as id doesn't appear to be a normal Realtek audio codec that can be made to work. USB audio would be an option for macOS. A Sabrent model can be picked up cheaply online and works great.
https://www.asus.com/Motherboards/ROG-Strix-Z270I-Gaming/specifications/
The following thread with be of some use to you:
https://www.tonymacx86.com/threads/...cpus-200-series-motherboards-in-macos.219877/
Yes both will work, the 1080Ti requires additional nvidia drivers to operate and is supported from the current macOS 10.12.4 public release available from the Mac App Store.
https://www.tonymacx86.com/forums/graphics.13/
https://www.tonymacx86.com/buyersguide/april/2017
Multi Booting UEFI is what to check out for running macOS and Windows on the same machine:
https://www.tonymacx86.com/forums/multi-booting.153/
