So I decided I make one topic for myself and all my questions (since I didn't find the answers in the few guides available!).
1. Is there any bootloader or SW version with which the phone is unmoddable? The bootloader opens with pressing *,# and RED, or? Answer ASAP, I leave in an hour or two
Other questions when I get back with IT
2. I could use the difference between SW versions info (speed, sound quality etc) when you get the time. Answer me on the 1st Q now