I'm in agreement with the others, I think your dad got screwed over

I'd always be wary of a used computer anyway, but this one sounds like it has its fair share of problems. Like GeekyPenguin said, I would get your dad to return the computer, as I'm sure he didn't buy it thinking it would be this much of a hassle, and have him go with you to the bookstore and get another one together (if you can go for the more expensive MacBook Pros, I'd do it instead of the G4 iBook - the G4 won't last you as long, simply because of compatibility down the line).
And a sidenote: as a previous iBook G3 owner (and current iMac G4 owner), I can tell you that the upgrades (memory, HD) you had on your old laptop will almost definitely not work with your newer one.
Good luck, I hope everything works out okay for you!