I've discussed some of the goods and bads [link|http://z.iwethey.org/forums/render/content/show?contentid=184560|here]. and in subsequent posts. Sound I got working by turning off the Mute button. I got the wireless 802.11b working by using ProMepis.
I haven't tried your Java update fix yet. Too many irons in the fire...
The Powerbook is a nice machine though. We've got a 667 MHz G4 TiBook with 1 GB of RAM. It's fine for web and Office stuff.
Cheers,
Scott.