1. I'll definitely reiterate what was said about the PSU - I have a serious distaste for cheap PSUs and the wrong one can seriously damage your system if you're not careful. I do not recommend skimping or compromising in this area as it's the most important part of the build bar none, and I can't stress that enough. Getting a a junk no-name PSU like that can quite literally blow up in your face - tread carefully. Here's some reading that I definitely suggest in this area: http://www.tomshardware.com/reviews/low-cost-psu-pc-pow...
2. It's mATX though and I never recommend going mATX on a full desktop system - there's a limited number of RAM slots (2 as opposed to 4), there's nothing in the BIOS that allows for OC'ing should you get an unlocked CPU later on, and you'll have limited number of SATA ports (4 as opposed to 6) so if you want to add any additional drives you're SOL.
3. I wouldn't recommend going that cheap on the case - Rosewill is a decent brand but going that cheap can often mean that the manufacturers will cut corners and there will be things like cheap / bad fans, loose wiring, no cable management, sharp edges that you can easily cut yourself on, things like that.
Would this not work as well as i3-2120? I know in the review above he compares it to intel cpus that don't have any discrete GPU, which is a bit silly.