how many overthrow can be done? If a fielding team do overthrow 2-3 times and the batsman take many runs in that, do the umpire interfere and declare ball dead so that no extra overthrow can be done in that particular ball.
There is (quite correctly) nothing in the Laws of Cricket which would mean that the umpires would declare the ball dead. If a team is stupid enough to keep throwing the ball hard at the stumps after they've missed three times already, then they deserve to have the batsmen keep racking up the runs. They can always just walk the ball to the wicket.