Play Certificate; Password to boot; Efuse blow:success

[OLDsheep]

Hey there,
Today I moved from a Mi Max (hydrogen) to a Redmi 9 (lancelet) and got some doubts:
1. Mi Max (on MIUI 10) had an option to ask for a password to boot the device. Note that this password was asked before the boot. I'm not referring to the password asked on the lockscreen after booting. I did not find this option on Redmi 9. Does it exist?

2. An "e blow: success" appears on the bottom left of my screen when the device boots. Is this normal? I assume the phrase is cut due to the round corner of the device, as a search on Google returns "efuse blow: success", but I cannot figure what it means nor if it is normal.

3. I can install Netflix and all apps from the Play Store with no problems. However, if I open the Play Store, go to "Settings" and scroll all the way down to "Play Protect Certificate", it says my device is uncertified. Is this common?

I'm running MIUI 11.0.8.0. I checked on developer settings and the bootloader is locked.

Thanks

Update: after the MIUI 12 update, the Play Protect Certificate says that the device is certified.

 

[mhark.moby]

let me answer the second and 3rd, yes we are the same as yours.