One thing which I forgot to put it, I have SecuROM on this computer because I haven't used cracks yet. Could I use cracks on my brother's computer so he doesn't get SecuROM, and still put in my backups? (Sorry if this sounds really dumb, I'm just making sure I cover everything so I don't break his computer or anything).
So basically, I'm going to hire the original Sims 2 (I don't own it, I borrowed it from a video game shop when I installed it, so I just put the EPs on my computer) then I can just put all the cracks on, (begone, SecuROM) and then just replace the Neighbourhood files and add a downloads folder.
I forgot to mention, he doesn't have the Sims 2 on it.
(I'm really sorry I forgot to add that, I swore that I put everything down on the first post so to not be a bother). But I think I've got a good idea now, just install everything then change bits which I want. Thank you, Snowbawl, for your help.