Here's what you should do. If I understand this correctly, borrow your friends Splinter Cell game, install krayzie's SC installer, return the game, then instal krayzie's SCEEE installer and you won't even need the disk to switch gack and forth!
If you're never going to go on Live then don't worry about SCEEE, but who knows if you'll ever want to be able to switch back and forth quickly and easily.