RE: What is center shot?
Center shot is just having the arrow pointed in the same direction as the string and cams are traveling when shot.
One way to check it is to nock an arrow and place the bow on the ground pointed away from you and then look down the bow and see if the arrow,string and cams are aligned and then look and see if the arrow runs a straight line with the limb bolts and stabilizer.
Of course this varies slightly from bow to bow but is a good starting point.My centershot is slightly to the inside of the stabilizer and that seems to be normal for some but I have never seen one that centershot was outside the stabilizer.
You need to set it and then do some group tuning.Get at a comfortable extended distance and shoot groups,make slight adjustments left and shoot more groups and then move the rest right and shoot more groups and when you start shooting your best groups you will most likely be very close with centershot.Make sure you make very slight adjustments and check it several times.I like to do it over a couple of days just to make sure it wasn't a fluke the day before.
Centershot has a HUGE affect on shootability and forgiveness.IMO this is the most critical part of setting up a bow after getting the spine right.