NO, NO, NO shot clock. Coaches are NOT here for fans or parents entertainment. Coaches are here to win basketball games. So holding the ball or stalling is a strategy in most cases. In the games I have seen where a team held the ball, the team on defense stood there with their hands on their hips looking at the offense. It goes both ways. If the defense would apply pressure defense, most teams wouldn't be able to hold the ball long anyway. On the flip side, if a team is disciplined enough to hold the ball all quarter, then I would call them a well coached team. Another theory behind holding the ball is that it gets a more talented/athletic team out of their offensive rhythm.
I can tell you this. If I am up 20 and a team is sitting in a zone (this has happened countless times to me), I am forcing you to come out and play defense. I will hold the ball the rest of the game if you can't defend.
So, in my opinion a shot clock isn't needed. Apply some defense and teams wouldn't be able to hold the basketball long anyway.
Another argument. Instead of adding a shot clock, why not have make it where teams are not allowed to play zone defenses. That would make it more difficult to stall.