I somehow lost the 2009 adapter in my apartment, so I have to grab my spare from work before I can test it again.  I'm currently using the 85W with the G4 as intended, and everything seems to be working great.  I think the Intel mini is fine too (fingers crossed), I was just worried because I ran it on the 85W adapter for a little over an hour while I was installing 10.9 and setting up user accounts.