I have ben reading a lot on this forum, but I am a noob for this and require some assistance. Maybe I am in the wrong group but i couldn't find the right place where i should post my questions.

Let me explain: I have an Iphone 3GS 32GB with SW version 3.0, jail broken and unlocked in Hong Kong. So far everything works fine and when changing cards for carriers while I am in Europe and china works flawlessly.

I have seen different customized software versions of 3.1.2 on the internet. When I upgrade to 3.1.2 with one of these versions, I want the same again as I have now for my Iphone (jail broken and unlocked)

My computer is with Windows 7 OS and have no easy access to a MAC.

Questions:

1) Can anybody advise me to a customized software version of 3.1.2. that I need when I want to go from 3.0 to 3.1.2. and still have a device that is jail broken and unlocked for use in china and Europe?
2) After installing this customized firmware 3.1.2 version with ITunes 9.01, will my baseband be upgraded or not?
3) When I perform this upgrade to 3.1.2 and the baseband is not upgraded, will I be able to unlock & jailbreak again in the future when the new baseband is cracked? (With respect to the warnings of the devteam and announcements from Apple to fix the unlocking)
4) I see customized SW versions that have small and big root partitions. What is actually the difference between a small and big root partition? More pre-installed programs?
5) What should I definitely NOT do while upgrading to turn my Iphone 3GS into a useless phone or expensive IPod?
6) Would it be better to stay on 3.0 instead of upgrading now?

Thanks for all your help!!

1) the best way is to use pwnagetool to make your own customized ipsw

2) if the ipsw is made with the current pwnagetool, baseband update is completely removed so no chance

3) yes the only thing that changes is the actual firmware version, the baseband is left alone in its hackable state, when another baseband becomes hackable you will have to restore with an untouched ipsw to update the baseband

4) the changed root partition is to make room for more cydia programs that dont reside in the Applications folder which is moved to the media partition

5) DO NOT use a stock ipsw from apple

also if its officially unlocked you dont need to worry about the unlock breaking

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