1. No one really knows. Depends on a lot of stuff
2. It obviously depends on the costs/type of original investment... Some investments may never break even.
3. CPUs are irrelevant right now. Don't bother with them. Use only GPUs
4. Yes. Just transfer the coins to MtGox/TradeHill/CampBX and sell them.
5. Data directory: https://en.bitcoin.it/wiki/Data_directory
6. $1000000000.. Wait, no, I meant $0.01... No, that's not it. Maybe $10? $60? $0.97? $523?