1 Download MBM from click here and run to see your processor temp. If you have no overheating probs then leave well alone. I have set it to sound an alarm if my XP2000 goes over 70 centigrade.
2 1 gig of ram is more than enough.
3 I have two 12 centimetre fans, one at the front pulling air in and one at the back taking air out. Again more than enough.
4 Hard drive fans do work to a certain extent but they are very noisy. You should only use these if you are having definite problems with the HD overheating.