I do not have access to the download section, and neither can i buy access as I am under 18 and don't have any credit cards or things from which I can pay.

If I do use the R1GB001 main file, then will it make any difference after reflashing? I mean will the bugs present in my current firmware be removed if I reflash to the main firmware as R1GB001 and the FS as R1KG0001. (R1KG001 is the latest firmware for my phone)

Also, after reflashing, will I need to customize my phone?