Whenever I game, my computer gets really hot. I don't think I have enough fans to support my rig. My brother has about 1-2 more fans than me and when he's gaming, there is no temperature problem. How many more fans do I need so I don't have the temperature problem? I do believe he does have a better heatsink than me but other than that, the same rig.
The obvious solution to me is too get an aftermarket heatsink for the CPU, as so far you haven't indicated that your not using the stock heatsink.
Something like a Hyper 212 EVO is fairly good for its price ad is much better than stock.
Coolermaster Hyper 212 EVO. $35 http://www.newegg.com/Product/Product.aspx?Item=N82E168...
As for whether case airflow is an issue, stress the CPU again but have the side panel off. If the temps improve significantly, then theres an airflow issue.
Slim coolers don't perform much better than stock. Comes down to simple physics, need more surface area and metal to dissipate the heat.
And looking at the design of the baseplate on it I can see why your getting 50c idle temps.
Take the side panel off and run a game. If temps improve by a lot, then you know case airflow is an issue, so you should get more fans.