I was able to confirm that the NFC worked by ordering an NFC tag. I used my Samsung to program the tag (which can be anything) to open the ifixit page. I then touched the tag to the top of the iPhone and it worked. I noticed that the NFC is not in the wireless charging coil as when I put the tag there it doesn’t pick up.
I just call it the bottom grounding bracket flex. I have attached an eBay listing of one hopefully that was a pointer in the right direction https://www.ebay.co.uk/itm/Appel-iPhone-X-bottom-bracket-with-flex/202810936794?hash=item2f38794dda:g:...--v
Im pretty sure that you can replace anything from the face ID unit event the ear speaker bit because Apple has tied it all together and the only way to get it repaired is to go to Apple at this moment in time. If someone can confirm this that would be good as I’m not 100% sure.
It’s either a faulty screen or you have done something wrong with the repair. I would start by reconnecting the flex cables and testing it. If that’s not the issue get a known good screen that you know is working, maybe a genuine one off eBay or get another one to test it with. If it’s not that then you might have done something wrong with the repair most likely put the wrong screws in the wrong holes causing longscrew damage. That’s hard to repair and you need to do some micro soldering to do fix that.
You can just get a glass only repair done so that the screen will be separated from the cracked glass and a new one would be installed. Or you can get a whole screen replacement that would replace the glass and screen. If you want to be cheap you could always put some clear tape over the glass until you get it replaced?