Coach physically assists

[BretMan]

The first thing I would say is that maybe you are putting too much emphasis on the coach's position. Being in or out of the coach's box isn't really a factor in calling this. The rules allow coaches to be out of the box while directing runners.

I don't think you're going to find specific interpretations for each of your scenarios, or any sort of all-inclusive list of every possible action by a coach that can possibly be interference. Each separate incident would be at the discretion and judgment of the individual umpire observing the play.

My personal belief is that you should be looking for willful and intentional actions by the coach. It is possible for a runner and coach to accidently make contact and that such contact can be ruled as incidental.

There was a play in MLB last year that was discussed on the baseball boards. A runner who rounded third was putting on the brakes and slipped in the grass. As he stopped, he barely brushed hands with the third base coach, who was standing in one spot giving the stop sign. It didn't appear that the touch was intentional on the coach's part. The 3B umpire called the runner out for coach's assistance.

The consensus of umpires commenting on that play (with the luxury of making the call from behind their keyboards after seeing multiple replays) was that they did not consider the coach's actions sufficient enough to consider it "assisting the runner". The seemingly unintentional "slight brush" of the runner's hand did not in any way alter his path, change his momentum or affect his decision to either advance or retreat.

I guess that two different umpires could judge the same play differently!