Indicator stalk intermittent: contacts wear out, just replace the stalk
Drivers door not activating interior light: will be dry joints in the lock mechanism, dismantle and re-solder
CD changer lights: you might just need an illumination loom, pull the CD changer out and have a look if one is fitted http://www.seatcupra.net/forums/showthread.php?t=113637&page=2
Window problem: could just need a new switch
Drivers seat heating: I'd swap the roller switches over and if the problem still persists I'd probably look to replace the heating mat (or at least remove the seat covers and look to see if it