I just checked mine after 90,000 for the first time, and they were all in spec bar two. Did you ever see that thread on a woman who had 200k on her Fazer. You can download her maintenance Excel spreadsheet and hers were only starting to go out of spec at 160k miles, as I remember. Yamaha's 5 valve design is very lightly stressed, so they don't need doing anything like as much as other bikes.
And yes, loads of crap drops onto the cams when you take the cover off! I found an allen bolt I'd lost down there! Workshops have compressed air and always blow out the spark plug holes before taking the lid off to get the crap out first. I bought a can of compressed air (pretty useless but it helped a bit) but loads of crap was still in there.