Gilby Clarke wasn't bad, but he wasn't writing great songs either.
The Spaghetti Incident is still a joke between my friends and I.
As far as the timing and whatnot... you're right, Metallica was pretty big, but they weren't a household name... Guns N' Roses was infamous *and* famous... everyone knew who they were. Axl is a bit of a prima donna and I think that had a good bit to do with it. Like I said, I think he was just absolutely astounded that people were moving away from GN'R to Nirvana/grunge. Got really pissed off and fell down.