I'd originally downloaded the nogapps without su and added Magisk.zip after, this caused an instant bootloop. The one with build in gapps+su works. It's possible to disable all gapps and related services except GoogleOne (I installed OpenLauncher into /system/app then removed GoogleOne by force). After this "Google" can be removed and all notifications about Google Services end.
I recommend you take down the twrp and remove the line which mounts the firmware partition as sdcard in case this is what wiped your IMEI. I build my own without this line and IMEI survived.
Wifi hotspot is working!
Bluetooth, camera, all USB,
Thee dots button (don't think it's a big deal as you get the three icons for back etc by default).
Auto screen brightness