Wow, you've pretty much described what I've done here. The 4 port usb hub miraculously works without needing power (I had a keyboard in one port and sync an ipod in another with no problems at all...i ruined the last port in my first soldering effort...)
As for caps, all you really need is static paper to lay down on the metal...that's what's done on the rest of the notebook where the logicboard is. Maybe I miss understood your point
There is space for another HD, but it'd be a really tight fit (unless you went with a 1.8") and then you need to find a way to power it (on my powerbook, the connector for the superdrive is identical to that of the HD but I doubt if it's the same interface beyond that, and I don't have the guts to risk it and try). But I suppose there are external HD's that are USB powered now, so I'm sure you could easily gut one and drop it in.
I let the IR port go awhile back.
I'm keeping the same LCD panel that was in the powerbook to begin with, which was 1024 x 768. The touch screen itself comes from a company called keytec, who sells their stuff through magictouch.com . Not the highest grade stuff (meaning it feels like trash after playing with iPhones/iPod Touch's).
Anyways, turns out I left the LCD screen at home, so here's a shot of the stuff sans screen and some structural innards.
