Restoring system partition in TWRP I've got an android phone running Android 6.0, with TWRP, Xposed, Busybox &amp; SuperSU installed on it (Not systemlessly though). Before I changed anything on the device, I temporarily booted into TWRP and created a Nandroid backup of all the partitions.

My device has now received an OTA update to Nougat 7.0, so,

Would restoring the system partition in TWRP break anything? 
&nbsp; or would it just restore my device to stock Android (allowing the OTA update) with all my data intact?
You need to restore the /system, boot.img, stock recovery also.  Your data should be fine, but as always, you should back up just in case.  The OTA will check for all three of those things and if they are modified at all (like when rooting), the OTA will fail to flash on your device.