If they are looking scratched, buffed, then is an issue with the player tray assambly (not the laser). try pressing "STOP" before "EJECT" so you allow discs to spin-down - that should be done automatically if you press "EJECT" from "PLAY" but maybe it is not happening.
If the surface of the discs looks smooth, that try burning those CD's at lower speeds, not "MAX" - usually 8X should provide the best results. Why they start "fading" from last songs? That is the OUTSIDE part of the disc and that is the part that is written with the highest linear speed (by most modern CD/DVD-R that employ P-CAV burning), so it is most prone to dye fade out.