iMac Questions

Long-time /g/ resident, had to use a Mac because that's what the computer lab here at my school is full of. So I fell pretty hard after a couple hours of using it, and now I think I'm going to go hit best buy next Wednsday and pick up an iMac.

Two questions:
1) Should I pick up some RAM while I'm there? Or rather, how does OSX handle with 1GB? I won't be doing any VMWare stuff or anything like that, just schoolwork. I don't want to get it if I won't need it.
2) I'm paranoid, and these things are expensive, can I run a bike lock through the hole for the power cable? I tried to see what held the base to the main assembly by looking at disassembly guides, but none of them showed the back. What is the base attached to?

Now I just need to work up the nerve to delete all my lol, macfag macros.

 

Kensington locks suck, and are way too thin (cable) anyways. I just need to know how easily the base would come off.

Does anybody really know when and what will be upgraded? I don't need a quad-core or anything... Do they pull all the models down one when they release new hardware or what?