Re locking boot loader.

Hello! I just got a nexus 6 a few days ago, and I love this phone! However, I just read on here that relocking your bootloader is a bad idea? Well, I rooted my device and installed PAC ROM on it, then reflashed a stock image back to my nexus and relocked the bootloader, my phone is fine, no bootloops and no issues, does this pose a problem with OTA updates? Thanks! I really need to know because i would NOT wanna brick this thing! Thanks!

About the SimCard locking

so i really don't know if i am in the right sub, but let's hope so

so i bought the S5 from germany about 3 days ago, when i returned back to my country, i noticed that the phone ONLY accepts european simcards so i am locked out of using the phone for calling or texting or anything

so i searched alot and found an app which required rooting
and i found some website which will provide codes to unlock

so i am really lost here, what should i do?!