JJEgan means it's really hard to get to brick your SGS.
The kernel is responsible for the proper functionality and cooperation between hardware parts. As for SGS, it is a common belief that Samsung's RFS is not as robust or "agile" as ext4 FS. Thus, converting RFS to ext4 should increase device's performance (the time needed for the read/write operations to take place is decreased). BUT, in order for the device to function properly, the kernel
MUST support ext4 as a file system format otherwise it won't work anymore (This could happen after installing a stock kernel on a device that uses some filesystem apart from rfs). Samsung's stock kernel
does not, so you have to replace it, if that's the case.
(E.g. If you format a USB drive under Windows 7 with "exFAT" as its filesystem, you won't be able to access it through Windows XP for example, because XP does not support "exFAT" - Different kernels
& Different OS version ).
Yes, CSC and modem.bin are what makes your device a TELEPHONE, too
Connectivity issues between your operator and your handset depend on those files. If you can find the latest COMPATIBLE modem file, then go for it.
Boulmpos - Ventrilogreek91
Samsung Galaxy S
Firmware version: FroYo 2.2.1
Darky's 9.5 Extreme ROM based on XWJS8 with Damian GTO firstname.lastname@example.org GHz themed by "a theme of my own :P".
Simple as that, in the free world of AOSP...