Haven't been on the forum in a few days.
Regarding your hand guard, if it is far off center and you shoot off a bi-pod, it might cause some problems as the rifle recoils but I'm not sure. My Gen 1 hand guard was off also. I just loosened up the allen bolts holding it on at the receiver and put wooden wedges between the barrel and hand guard where the barrel exits the hand guard. I moved them until the barrel was centered in the hand guard and then tightened the bolts. It stayed centered after that.
I had my bolt body and bolt handle Micro-Slicked (black) by Zephyr Defense to get rid of the "zipper" sound. I think they have a web site (I had mine done through the Ruger Precision Rifle page on Face Book, good info there). Micro-Slick is made by Cerakote and it is sprayed on and heat cured. I did both the bolt & handle so the color would match. It was in the $45 - $50 range including shipping. Picture attached.
I shot the Hornady 129 grain Interlock during break-in (I know, everyone says you don't need to break in the barrel but it can't hurt). It shot OK with it. I have shot some of the common factory loads through mine including Hornady 140 gr ELDM, Winchester 140 gr Match and Federal American Eagle 140 gr OTM. All of them shot very well at 100 & 200 yards but I have only taken the Hornady to distances past 200 yards and it has shot well. I have all the stuff to start reloading and will start developing a load soon.
If you want to try different ballistic apps for your phone, I have tried a few free ones and then finally paid for Strelok + (there are 3 versions, Free, + and Pro). I am happy with it.
I know this reply is a little late but hope it helps.
That bolt looks sweet, I'm looking for an at home solution though. I'll try flitz on the bolt/ receiver, thanks for the rec on strelok, I just plugged in some factory numbers on jbm's calculator... Saturday seems like an eternity away.