when air cooling via heatsinks, the faster the air speed, plus higher the air volume the better. Theoretically, and we are talking extreme, if you had a handful of crazy fans, and for some reason an ungrounded device you would generate static electricity via friction, etc. All devices are grounded so without a wiring fault (AC OR DC), or you touching physically touching something to transfer that static energy, you won't have a problem.
Things that can go wrong that you can adjust/fix:
*fan that gets pointed in the wrong direction (it happens)
*case fan somehow pointing just right at smaller video or northbridge fan that causes it to spin faster than designed and bust a bearing (happens more often when someone uses compressed air to clean the heatsink, but the noise is usually obvious, high pitched weeee.)
*dead zone around the cards where no air moves, re-aim or add fans and venting as necessary.