[mbyron]

1. The balk is charged to the pitcher because he's the one who balks, not the catcher. There's no violation for the catcher standing in the wrong place; there's a violation for the pitcher pitching when the catcher is in the wrong place. The term 'catcher's balk' is common but misleading, since it really is (always) the pitcher who balks.

2. Interference on a batted ball may be intentional or merely negligent. Interference on a thrown ball must be intentional. In the case where R2 is hit by a batted ball, intent is not necessary for the interference call: R2 must get out of the way (note: not merely try to get out of the way), and if he doesn't, call interference. (I'm ignoring the qualification about runner being immediately behind an infielder playing the batted ball...)