I use mostly the D4 for sports but the D800 is my second body.
As the last poster mentioned, auto and 3D are not very useful. I either use AFC-S or AFC-9 most of the time, the single point when the area is crowded especially with a long telephoto (i.e. where the single point covers a lot of people-space).
Be sure to take some test shots of stationary objects that are good focus targets (lots of contrast, isolated from nearer-further objects, good strong horizontal and vertical lines). Be sure you know what "good" is; with the 36mpx image viewed 1:1 (what most people do), it is important to realize that the definition of "in focus" changes a bit, as it is much like zooming 2:1 or 3:1 on other cameras.
IT is controversial, but I also believe you need to at lest check all lenses to see if they need fine tuning. My experience with one camera, and listing to lots of other owners, is that there's more variation here than in less demanding cameras, and fine tuning is important (to give a nod to the contrary opinion, many will tell you not to look for a problem you may not have).
I think similarly IF you are using the pixels to crop heavily, a higher shutter speed than normal is called for, as you see blur across pixels with less motion simply because the pixels are tinier (conversely though if you kept the same framing and downsize, i.e. do not crop heavier than normal, it's all the same).
I don't know the 70-200/f4 and 1.4TC; I will tell you on the 70-200/2.8 I never use a TC as it makes it a bit too soft. The 1.4's effect in general, however, is pretty mild. Be sure to shoot a few without just to see. And if you do fine tune know that it's a separate setting with and without.
Also look at the release priority (will it shoot if it's not in focus) and the Lock-on (A1 and A3), as these effect how focus works when shooting fast or against moving targets. The technical guide has good info on that.
The D800 is a fine sports lens if you understand its limitations. You sound like you know the FPS part. Just be aware that it's easy with the 36mpx to be overly-critical of your shots. When reviewing them on a computer, most people just hit "enlarge" or whatever serves, and get the 1:1 view, and say "yuck" without really thinking it is like zooming MUCH further in than they would on a prior camera. The slightest flaw in technique then becomes visible, not because it's a new flaw, but because you couldn't see it on your other camera.