Volume balancing is what it sounds. It just adjusts all the tracks on the same level so you wont have one track loud while the next track soft. It will put all the tracks on the same sound level. I don't see the feature any usefull to tell you the truth. I might even mess up the quality of your songs.
Bootable CD is just when instead of your computer booting up from your hard drive it boots up from the disk. If you plan to burn a bootable disk (system file, appl) then you can selsct it, but if its for games, music, movies no need to select it.