pipe tobacco often has a casing on it. for that reason i wouldn't vaporize it. and also the tobacco might not be air cured. there is the option of growing your own then you can be assured it was air cured. you could try vaping snus (or even using snus full time) as snus should always be air...
yeah don't google too much.
surely one could wrap aluminium foil around the heating element to stop the bits flaking off? haven't tried it but might work - the heat would still conduct through the foil i imagine.
or maybe using it for 5 years is too long... anyone else?