I used dc-unlocker from this tutorial https://forum.xda-developers.com/honor-7x/how-to/how-to-unlock-huawei-bootloader-removal-t3780903
for mate 9 you can use dc-unlocker app instead of hcu-client which is easier
you have to pay 4 euros
you guys have no idea what you are talking about, even without thermal_engine the phone will still throttle
no. Install the sense.zip folder after you install the latest version.