Baseball rules question

[doucy]

I was watching a Red Sox game the other day in which Schilling was pitching. There was a situation in which the bases were loaded, 2 outs, 3-2 count. So the runners are moving ldo.

When Schilling made the pitch, he went through his entire windup rather than pitching from the stretch position.

2 questions:
-Why would he go through his entire windup? Seems like this could turn what would normally be a 1-run single into a 2-run single since the runners are moving.

-Rule question. Since he went through his entire windup, the runner on third was well on his way to home by the time the pitch was thrown. Hypothetically, if the runner were to make it home before the pitch reaches the plate, then the batter grounds out, would the run count? The inning ended on a force out so it doesn't matter if a run scored first, but technically you could say the run scored before the play even started. What if the batter struck out instead of grounding out?