Upping the idle is a cheap way to get around the problem I suppose.
It does very much sound like a AFM. A bloke I know with an r32 had problems with his car dying on the road, we suggested giving the AFM a hit with his hand which promptly stalled his car (once you get breaks in them little hotwires - its goodnight). He has replaced it now, and everything is running like a dream.
Only way your going to really tell, is if you start checking signals returning from AFM's and by measuring your injector pulse width. If the coolant temp sensor is borked, your car will be running rich the start with and foul your plugs - which unburnt fuel will kill your O2 sensor and your cat.
Cheers
Sumo