I think my handoff/continuity also doesn't work (I recall reading somewhere that there is some trouble getting that set up...). I haven't tried it, nor do I use it commonly, but I did try it once but to no luck. Hopefully there's a solution to this (I would certainly want to have this feature lying around!).
May be wrong on this, but I think through HDMI you can only peak out at around 30 fps using the iGPU. If you want 60 I suggest switching over to DP (but that carries problems on its own, look through the thread).
Not sure about the crossed-out circle (that never happened to me). Did you start with Mojave or High Sierra? OP's EFI is for HS, not for Mojave. Maybe try from the start (from HS), and then make your way up? (I know there are graphic errors using OP's EFI in Mojave; some things need to be changed)
As well, OP uses 18,3; which does pose some problems. Odd though, I'm using 18,1 with no problems...did you try that?
USBs should be customized by yourself. RehabMan has a guide somewhere (
https://www.tonymacx86.com/threads/guide-creating-a-custom-ssdt-for-usbinjectall-kext.211311/). This guide (
https://www.tonymacx86.com/threads/applehda-hdmi-audio-guide.234735/) should do the trick for HDMI audio.
This is my first build, so I may not be as experienced as others that may be in the thread. A quick search in the thread would definitely help solve some problems.
EDIT: Slightly looked into your EFI. If you're on Mojave: MAKE A BACKUP FIRST (in case something goes wrong)! Take out Shiki and IntelGraphicsFixup and use WhateverGreen. Someone suggested using 1.2.4, as 1.2.5 caused some problems? Don't quite remember, but give that a shot. Take out the Fake IntelGFX ID, and use in Graphics --> ig-platform-id "0x3E920000" or "0x3E9B0007"
These are steps you can try out, but I don't pose these as solutions. Do try at your own risk (and make a backup!)
The Wifi/BT chip is actually relatively simple to install. All you need is a lot of patience and PLEASE a magnetic screwdriver (I don't have one, and boy it was hard). On the MB look for the wifi box thing (it's where the antennas connect to), then unscrew any screws (on the MB and on the box) that you see. Remove the encasing, use some force to disconnect the wires from the original Intel wifi chip, then attach the new one (watch the orientation!). Put everything back to place and the chip is installed.
There are a few guides talking about how to install Broadcom Wifi chips in macOS (this is a good start:
https://www.tonymacx86.com/threads/broadcom-wifi-bluetooth-guide.242423/).
I use my Hack as a dual-boot, and it works perfectly fine! Make sure to use two drives, as then if something goes wrong it doesn't affect the other OS. The only small problem I've encountered is the time of day when switching from one OS to another—on macOS it may be off but immediately changes to the correct time, while in Windows it does take some time for the automatic time setting to take place (I generally manually override the automatic time setting so that Windows sets the time correctly). Using one OS will not have this problem; it only occurs when switching.
Note that Mojave has many NVidia driver issues right now, so be wary when installing your eGPU in.
The EFI that
@erik attached does have SSDT files, however I still suggest you create it yourself in case (I provided a link above)
I don't think there's too many catches for the i7 (maybe for power management?), but I don't speak from experience. Does someone in the thread use an i7, and if so provide some insight?
Why did you need to move the ethernet cable in between? I just plugged the USBs in