Can an LG 5163D operate effectively when attached to a laptop with a 64 MB video card, rather than a 128 MB card, as recommended on the LG box?
Yes. Video memory has zero effect on the ability to use any optical drive.
Usually this is a recommended video memory for the software provided with the drive; but I have to say it does sound like an over the top recommendation. It certainly won’t bother the operation of the drive.