ElkOil's post in Is the runner at first base forced to run on a batters hit? was marked as the answer
No. Once the batter-runner is retired, the runner at first can retreat because the force was removed once the out was made.
Think of it this way: the runner on first was forced to run when the batter became a runner. Once the batter-runner was out, nobody is forcing the base runner to go anywhere anymore.
ElkOil's post in strike 3 hits batter was marked as the answer
Any time a pitch hits a batter, the ball is dead. Period. Next, the umpire decides if the pitch was a ball or a strike. If it was a ball, the batter is awarded first base. If it was a strike, the batter remains at bat or is retired if it was strike three.