NBD, just another baseball scoring Q

TO be a sac, the batter has to be out or safe on an error and a runner has to advance (doesn't matter if it's the lead or trailing runner).
If you want to call him reaching on an FC, go ahead. However, the reasoning behind it being a base hit is simply to not punish the batter for performing his job correctly. If the play is made, he gets a sac, no at-bat.. If it's an error, he gets a sac, no at bat. If you give him a fielder's choice and no outs are made, he has done his job correctly, and get's first base but is punished for having an at bat.

 

Oh and in your above question, if the throw is to third and all are safe, he get's his sac, which is the lone oddity to the rule in the MLB rules. T

 

This is a simple fielder's choice sacrifice.
The fact that he "would have been out by a mile" at first means no hit.