MY BARREL IN MY 90-SERIES PISTOL IS NOT CENTERED IN THE SLIDE; IS THIS A PROBLEM?

This is a normal and common condition on 92 Series firearms; it does not affect function or accuracy.
From Beretta:

90-Series Pistol Barrel Alignment

Updated 3/12/19

Frequently, our technical division receives inquiries from concerned consumers, stating that the end of the barrel on their Beretta 90-series pistol is not centered in the end of the slide (as depicted below). Owners are often worried that this feature is a defect, and/or will negatively impact accuracy or safe function. Fortunately, this is not the case.

This feature is a normal characteristic of a 90-series pistol. The barrel is secured into position by the locking block design, which, in turn, holds the barrel firmly within the slide when in battery. However, the orientation of this mechanism often results in the barrel resting off-center within the assembly. This condition does not have a negative impact the accuracy, nor does it negatively affect the functionality of the firearm. Some pistol designs employ the use of barrel bushings (such as in a 1911) or other components, which often results in uniform parallel alignment between the barrel and slide. However, 90-Series pistols conspicuously omit these features.  

Subjectively, this feature may render the firearm less than aesthetically pleasing. However, no corrective action is necessary. Notably, heavy usage will often result in a somewhat oblong or rectangular wear pattern in the parkerized/anodized finish of the barrel, manifesting at the point where the barrel contacts the side of the slide or along the barrel top, where the “bridge” maintaining the front sight post rubs along the barrel. This can be maintained by oiling the barrel with a moisture-displacing lubricant, as is routine in firearm maintenance. Doing so will prevent the barrel from developing rust. If the consumer wishes, the barrel may be re-finished as needed. However, this is typically at the cost of the consumer, and the wear pattern is likely to re-develop during normal use.

Models affected include, but are not necessarily limited to:

92FS, 92A1, M9A1, M9A3, M9 Commercial, 90-TWO, 92X, etc.

All 90-series pistols are proven designs that meet military, law enforcement, and commercial requirements for reliability and accuracy. However, if the need for gun smithing services remains/becomes evident, please contact us at 1-800-BERETTA, ext. 2003. Please have your serial number prepared.