Good number of fans for this case/system?

Hello,
Im gaming on my computer that has the following set of specs: gtx 660ti, 16gbs ram, i5 3570k, z77 motherboard, coolmaster 500W; this is the case: http://www.newegg.ca/Product/Product.aspx?Item=N82E1681...
the processor and graphics card have fans but I was wondering whether it'd be necessary to get fans for the case. I would also love to know what temperature I should set the graphics card in bios for an emergency shutdown (my friend set the temp up for me, so the computer keeps restarting after a couple minutes of far cry 3; guessing the graphics card is overheating  ?). Finally i'll mention that I had another power supply on this setup that started smelling funny, and eventually burnt. I replaced it with the 500W coolmaster; do you guys think it'd be necessary to get a 750W corsair? The listed components/hdd are all that I have and the only thing I do is game:S so im not exactly sure what the smartest thing would be. I think thats about it. Kinda splitting hairs here, but any answers are much appreciated.