1. Yes, your parts are compatible. You might be better off getting a cheaper motherboard since your processor is locked.
2. The 100 and 200s are a decent case, but for the same price you can get the 300 from newegg for 45dollars. The main things to look for in cases is airflow, cable management, and how sturdy the build quality is.
3. Yes the CPU and Mobo is fine. Unless you are getting the PSU in a crazy sale or something, there are better PSUs in that price range. Like the XFX Gold rated 550W or even the OCZ Pro 700w went from $130 down to $60. The amount of power you need depends on what video card you will want to put in the future, but if it is anything between the mid-high end I suggest going a little higher on the wattage.