Don't feel so bad about having an i3. If yours is a Sandy/Ivy Bridge then look at the 990X.
It's a 1000$ beast from Febuary 2011 and got 1.2 in a single Cinebench 11.5 thread. The i3 3220 got 1.34. In many games the i3 will do better than a stock 990X

Also note that Intel can be assholes with naming. Tons of i7s in laptops are actually dual cores with hyperthreading, like your i3 and all i5s are dual cores with hyperthreading. The cores themselves have identical architecture.
For those other questions I'm not a good person to ask, the computer I'm building now will replace my 08 computer. Before that I had a computer without even AGP...