If done properly, you cannot do true damage to a ball surface, except for the fact that you take away material.
If the ball does not seem to have enough bite, there could be a) too much surface for the condition you face, b) still too little (or it was not done thoroughly) or c) the ball could need an extra oil extraction.
Hard to tell. A sanded ball tends to grab the lane earlier, so the hook is distributed all along its way down the lane - the coarser the finish, the earlier and more even, until the grit becomes so coarse that the ball actually loses contact area with the lane, but this only happens with VERY rough surfaces (220 grit or even less).
--------------------
DizzyFugu - Reporting from Germany
Confused by bowling? Check out BR.com's vault of wisdom: the unofficial FAQ section