Mi4s Xiaomi.eu Update

I have purchased Mi4s from Honorby web site 6 months ago in Croatia. I got it installed with MIUI by xiaomi.eu 7.2Stabil 7.2.5.0(LAJCNDA) and i have a few questions.
-do I have unlocked botloader because it is installed this rom?
-how to check if the locked botloader or not?
-how to update to MIUI V8?
-do I get the official update of Nougat if xiaomi send OTA or have to manual over TWRP and xiaomi.eu Rom

Thanks for the help, any information is welcome!