Question [Q] Some questions after reverting to STOCK ROM

Like many of you I haved rooted, unlocked with FreeGee and installed many custom ROMs on my LG Optimus G.
Now I decided to go back to STOCK ROM, I followed this GUIDE to flash KDZ, everything worked OK, phone works like it has to.
So if everything works what are the problems, well ... I have some questions for you:
1. Many of you are writing in the forum that after flashing the KDZ the phone will revert back completly to stock. Will it revert bootloader back to stock too?
2. If the answer of above question is that it will revert back to stock, then in this forum someone says that bluetooth gets its MAC adress from bootloader. Why my bluetooth MAC still begins with 41:4E ? Is this one of the compromises when you unlock the bootloader?
3. Is it possible that in flashing KDZ guide I did something that will not flash the bootloader?
4. Is there a way to fix bluetooth MAC adress?

Thanks in advance for your answers.