I'm so glad they chose Encounter At Farpoint. Not starting at the first episode would have been insane. The other episodes seem somewhat arbitrary to me.
Not really--with further reflection--it spreads out the episodes over 5 seasons...which is good for a sample. Also, the Inner Light is considered the "City on the Edge of Forever" of STNG by many people. Including Sins of the father might be like including "Errand of Mercy" in a TOS sampler.