[Nevadaref]

1. I've already said that I wouldn't call a foul for the two guys doing a little paddycake in clip #1. I would simply tell them to knock it off and then watch them for the next two or three trips up and down the floor. I might even verbally announce to my partners that these two have been warned and to keep an eye on them.
I think that calling a foul for this action during a loose ball in a boys game is being too picky. I also agree with the poster who noted that the T was in a spot from which he couldn't really observe the action. I call this straight-lined or having a closed look. My terminology is different from what he used, but we are saying the same thing.

2. Those who want a foul for the player knocking the defender's hand away are crazy. That doesn't make any sense. If you are going to allow a defender to put his hand on an opponent continuously, without penalty, then you better not penalize the player when he pushes it away. Again this situation falls into the how picky do you want to be category. If you whistle anything here, you better penalize the first illegal contact not just the response. I'm still not convinced that a whistle is needed at this point in this particular situation, but given the earlier dust-up and especially if these two were warned, I'm okay with a double personal here.
I tend to manage boys games more with my voice and proximity to the players. The game is generally better that way than when there are lots of fouls called and FTs attempted.

3. The first hard contact in the second clip or contact with two hands gets a whistle and I'd close right in. Easier to do if the Lead has rotated.

4. To the posters talking about a T in clip #2, I hope that you are referring to after one of the players hits the floor and the ball is dead on a previous foul because the rules don't allow us to toss out Ts for live ball contact.