1) Just burn the whole LFS folder to CD or move it to another partition/hdd during the format. You keep everything then: settings, credits, setups, replays, skins, etc.
2) Why worry about credits? They're obsolete and serve no purpose what-so-ever.
More important would be you want to save the settings, skins, skins_x, spr, and mpr folders and not worry about the credits. Also I like to save the ini or cfg file that holds all your graphics settings and stuff. So, yea, it's probably just easiest to save the entire LFS folder. I always keep a CD-RW disk, my thumbdrive, or an old harddrive around for these purposes of backing up.