BB gave you some general rules on game delays. The real rule that covers what you're concerned with is OBR 4.15(b), where the umpire may forfeit the game to the opposing team when a player or coach "employs tactics palpably designed to delay or shorten the game."
The problem is, an umpire really can't use that rule when the team does things that are legitimate, such as making a pitching change, making a substitution, talking to the batter, etc. There's nothing illegal or improper if the manager wants to bring in a new pitcher after each batter, and you cannot stop him from doing that. You can only deal with things like you mentioned where the player or coach does something out of the ordinary.