I would say that sleeves are not the ideal form of storage for CD-Rs, but I don't think they'll destroy the disc either. I prefer a spindle if I will not be handleing the discs on any regular basis, and I use jewel cases for the stuff I use more frequently. I only use albums for discs that I do not use frequently, but need to be able to identify quickly on the odd occasion that I want to use them. For example: Movies, System Discs, backups.
Punch Cards -> Paper Tape -> Tape Drive -> 8" Floppy Diskette -> 5 1/4" Floppy Diskette -> 3 1/2" "Flippy" Diskette -> CD-R -> DVD±R -> BD-R
The Progression of Computer Media