don't really know what alignment and burr rub is about, though. Are those issues that'll affect me daily?

So, a burr-set has two pieces with cutting surfaces that slice in opposing directions, and the size of the gap between them is the size of the particles that it should make when grinding (ignoring the fact that brittle plant material doesn't shear cleanly and will always have some shattering). Ideally, the two pieces should be aligned perfectly parallel to each other so that the gap is the same size at every point around its circumference, and thus produces a more narrow distribution of particle sizes. When the burrs are very close together in the fine grind range, if they are slightly out of alignment they will rub against each other at the point at which their two planes are closest. It won't damage the burrs in the short term, though it might in the long-term, but more importantly if you are grinding for espresso, your grind will not be as optimally consistent as it could be for that specific grinder. Hence, preferring alignment that is a result of the design, instead of in spite of the design.