Computer upgrades such as external hard drives will be necessary especially if you shoot HD videos at higher resolutions. Technology is advancing and it is unavoidable. From what I have read, f8 would be the sharpest or optimum aperture. You'll start to see less sharp images if you view it at 100 to 300% view. For your typical print images, you might not see the difference.
36.3 mp will be enough once the release they 1440p monitors!