Re: XD .45 Tac. Accuracy Questions
Before you go adjusting anything, moving sights, etc., let some other people shoot it and see what kind of results that are able to obtain (i.e. - if your buddy with the Kimber is a good pistol shooter, let him shoot a couple of mags through it and see what his results are). The reason that I say that is that this problem could be any number of issues and it may not be the gun itself causing your accuracy/POI woes. Proper grip, trigger manipulation, follow through, sight picture/alignment, etc. are all possible sources of your problem. Many of these problems are only heightened because it doesn't sound like you have had any formal training or proper instruction into pistol shooting basics even though you have been shooting at least this pistol for a while now. Don't underestimate how even small errors in technique can create huge problems on target.
One thing many shooters with these pistols don't realize is that your sights may be setup to use a different sight picture than what you would "think" is correct. The sights on MANY of the factory SA XD pistols I have shot are 6-o'clock shooters, meaning that instead of the more tradition #2 image, you should actually shoot with your sight picture as #1 below. Based on your "orange" circle you drew for POA for the group you fired into the black, it is likely you have a 6 o'clock shooter/sight picture pistol. Even with that done, you would still be shooting left which could be a sight picture issue, trigger manipulation problem, or it could be that your sights are a little right causing your POI to be left.
** Thanks to NavyGuy on the SIGforum for the graphic **
After you get the pistol into other shooter's hands and see what kind of results they are able to obtain, you will hopefully have a better idea if its the gun or you. In the meantime, get some training (or at a minimum, do some reading/vid watching) on proper pistol shooting technique including grip, trigger manipulation, stance, sight picture/alignment, etc., etc.