I have to say 256 MB ram is not a lot for OSX. My LW often uses up to 500 MB ram.
You're eithr using your 56kbps modem OR you're using an ehternet connection thru your school. It's either one or the other. You internal modem's max downld speed is approx 7 KB/s.
You don't need a firewall for OSX!
Do you mean forcing ip did have some success for you? If yes, then that's a good sign!
Uni's are always a bit of a mystery b/c we don't know what type of limits they've applied. And they may decide to apply them anytime particularly if they detect p2p activity.
That's all for now before my head hits my keyboard. lol

I'll review this later!