No. A runner may not intentionally attempt to dislodge the ball as a fielder attempts a tag. However, if a legal slide or incidental legal contact dislodges the ball, then the runner is not out because the fielder did not control the ball throughout the tag. If the runner committed an intentional act of interference unrelated to running the bases, such as slapping at the fielder’s glove, grabbing the fielder’s arm, or flagrantly using the arms or legs to try and dislodge the ball, the runner would be out and the ball would be dead.
Misapplication of the Courtesy Runner rule (such as attempting to use the Courtesy Runner to run for someone other than the pitcher or catcher; or attempting to use a Courtesy Runner with <2 outs) would be a rules violation. The violation should be detected when the manager reports the use of the Courtesy Runner to the plate umpire. The plate umpire would disallow the incorrect use of the Courtesy Runner.
The courtesy runner is allowed only for the player who was the pitcher or catcher of record at the end of the last defensive half-inning.
B/R = Batter-Runner. The batter-runner is the offensive player who has just finished a time at bat until the play during which that player became a batter-runner ends.
No. This is a rule change starting for the 2021 season. If the batter reaches base safely, they need to score, be retired as a runner, or be left on base when the half inning or game ends for that At Bat to fulfil their offensive mandatory play requirement. If the batter is replaced by a pinch runner, special pinch runner, or courtesy runner, that time as a batter does not count as an At Bat for mandatory play.
No. The Courtesy Runner is a local option available to the offense only with two outs whether using the continuous batting order or batting nine.
Yes. A foul tip is a live ball and runners may advance.
Yes, unless there is a local rule to the contrary in effect for an Instructional Minors program.
Yes. The base is not a sanctuary for baserunners hit by a batted ball and the runner is out. Exceptions are if the batted ball has first been touched by an infielder, the batted ball has first passed through or by an infielder, or if the batted ball is ruled an infield fly.
This is a Time Play. Whether the run scores or not is determined by whether R3 scores before R1 is tagged out at second base (run scores) or R1 is tagged out at second base before R3 scores (no run scores).