Can I just flash firmware but not FS?

[anthonyla65]

Hello there, I'm new to here :) and I want to ask that I'm getting a K770i from ebay unlocked, but as far as I know, its Vodafone branded and I don't really like vodafone, so how do I debrand?

So I've been reading alot about debranding, so if its CID53, I'd have to use Far+JDFlasher or if its CID52 then XS++? What I'm unsure about is, do I HAVE to flash the FS + Cust. pack? I remember on my old K770i thats been burgaled, I bought it in hong kong, then updated through SEUS and lost chinese and it put EU firmware on it, but I couldn't be bothered flashing it back to chinese. I've heard something about, if you only flash Main, then if you use SEUS it'll revert back to the what it is. I don't mind that at all. Because I heard flashing FS can brick your phone but Main can't. Also lets say if I flash the Main + FS, do I need to flash Cust Pack aswell? I've got SOME experience flashing my K750i to W800i but Main only.

Well so far I'm looking at flashing with these files:
K770_R8BC004_MAIN_GENERIC_VI_RED53
K770_R8BC004_FS_EUROPE_1_RED53
HB1-06_Gen_CDA102568_10_R8A_GENERIC_EUROPE_1
or
for CID52
K770_R8BC004_MAIN_GENERIC_VI_RED52
K770_R8BC004_FS_EUROPE_1_RED52
HB1-06_Gen_CDA102568_10_R8A_GENERIC_EUROPE_1
Are those files right and match?

Please help me out.

Thanks in advance :)