In that case I need 3 and 4 explaining more and why to have each choice...
Ok, Cfn3-3 is pretty straightforward.
0 - means the camera won't fire until it has focus and will slow down the frame rate in order to better track the subject. Delay for first shot and reduced frame rate.
1 - the camera won't fire the first shot until it has lock but then will sustain the frame rate at the expense of focus tracking. Delay for first shot, max frame rate thereafter.
2 - the camera won't delay the shutter at all, for the first or subsequent shots. No delay, max frame rate.
Cfn3-4
0 - the camera will constantly look at the active point and see if it should re-focus. So if something moves in front of the subject it will adjust after the delay set in the tracking sensitivity
1 - new subjects don't become a priority, the camera will try and track the original subject.
These settings have little impact if you are using a single point with no assist although setting 0 will allow the shift to a closer subject on a single point once the tracking sensitivity delay has expired.
I use a single point and select one that will fall on a good contrast area of the subject, if they're wearing a plain top, esp. a dark one, I will normally switch to the face instead to give the AF more contrast. I'm also quick to release AF if the subject is masked by something closer so the camera doesn't re-focus and a slow tracking sensitivity means I have enough time to do that. I re-enage AF as soon as I get the subject back.
With regard to the lens having problems at distance remember that the further away the lens if focused the greater the difference each small adjustment will have. At close range it might only be a shift of a couple of mm but at longer range it's suddenly become 50cm so the micro adjust might only need a small tweak to bring the long range stuff into calibration without impacting the closer stuff. Of course there's only one way to find out...