Greetings!
I would like to go over the haptic issues first. For that you should make sure that the Taptic Engine is plugged in and making a good connection, then make sure the screws holding it into place are tight. These screen can get loose, and cause the engine to make horrible noises when activated because it is loose and shaking more than it should. You mentioned you scratched the wireless charging coil, but that shouldn't be problem. And the grounding clips or "spring connectors" are mostly fro grounding the antennas of the phone, and shouldn't affect functionality.
As the tweet that you linked in your post said , there have been may issues with aftermarket screens when updating to iOS 16. The new operating system introduced a new boot sequence that a lot of aftermarket screens are incompatible with. This primarily caused the iPhone 11 Pro Max Soft OLED aftermarket screens having touch issues and the iPhone 12 Pro Max Hard OLED aftermarket screens having no image after updating. I haven't heard of any iPhone XS being affected until now. This being said, unfortunately, I would say your screen probably is incompatible with iOS 16 and you need a new screen. It seems like the long press issues and grainy-ness you were having was most likely caused but a not-so-good screen to begin with.