One more question. Is bitcoin-qt just another bitcoin wallet, or does the client also make your computer a node on the Bitcoin network, thus offering your computing power and memory as peer-to-peer resources for the network and extending its backbone?
Bitcoin-QT is a wallet, a very secure wallet. It downloads the entire blockchain has a stronger backbone compared to other wallets.
It is not a node though.
If you want to run a full node, just run bitcoin-qt and forward port 8333 on your machine. https://bitcointalk.org/index.php?topic=128122.0
The CPU usage and RAM usage would be pretty low, but then you should notice a big jump in your bandwidth usage.
