Does my D800 have left AF issues?

Nice baby, but babys dont do as test targets.
You need to shoot a test target.

Do the following: put your camera on a tripod, focus on something static with your leftmost AF point an shoot. Then switch to liveview without moving the camera or target. Move the AF point in liveview over the target an shoot. Then compare images.

If image focused with viewfinder is much softer than that done with liveview you might have an issue.