The alignment will effect chain sprocket longevity, If it is even slightly askew, the wear will be uneven, at least that's the case in industrial applications. I was checking out getting one of those laser rear sprocket straightness guides. I use a long machinists straight edge now and I get good results, but that laser looks to be a lot quicker. BTW, You can flop a sprocket as well and get more use out of one to a practical degree.
