Noob questions about F210 firmware / flashing

[mchomicz]

I have flashed firmwares on many devices - DVD drives, satellite receivers, SLR cameras, MP3 players - to name a few; so I understand the general idea. But never a cell phone.

I have an F210 (purchased with no service contract - unlocked - in case that's relevant) and was able to 'collect' a few files (firmware images: F210XEGH1, F210XXGJ1, F210XEGJ2, F210XXGJ3 as well as OptiFlash_F210 - flasher for F210 I presume).

Below are my questions. Could someone please kindly shed some light - or point me to relevant URL(s)?

1. In general, what is the purpose of flashing firmware on a cell phone? Are firmwares flashed on cell phones because newer ones contain bug fixes? Or only to add / change features (such as supported languages)? Or is it to unlock SIM-locked phones?
2. Is there any way to figure out which firmware my phone has already loaded?
3. In order to flash firmware on my F210 using the OptiFlash software - do I need a serial cable? Or can it be done with the USB cable that was included with the phone?
4. Is there other software for flashing F210?

BTW - I become interested in flashing the firmware in the first place because the phone has a few annoying bugs / software shortcomings that I was hoping might have been fixed in a later firmware (or a custom firmware - if such things exist for cell phones).

Thank you,
Michael