1. Some mobos will downclock RAM to 1333MHz for safety purposes. Clocking it up to 1600MHz wouldn't be considered overclocking.
2. What? As far as I know, an AII 240 will run fine with faster RAM. Bus limitations are based on the mobo.
3. CL7 is pretty tight timings.
4. Get DDR3.
Btw, get the 240 from Newegg. It's cheaper ($57), and Newegg is probably more reliable than that memoryexpress site.
This is kinda unbalanced though. You should spend more on the CPU if you wanna take advantage of the faster RAM.