I gotta say, if it's actually stable, I'm somewhat surprised. I certainly wouldn't run it 24/7 at that voltage, but that's just me. If it starts crashing in the future while playing games, then at least you'll know why.
At any rate, you will get better airflow and therefore better cooling with a push/pull configuration (one side fan intake, one exhaust) rather than setting them all to intake, with an exhaust at the top. You want to get the hot air out, not just bring in outside air, and the idea is to have close to equal amounts of hot air exiting the case and cool air coming in.