I also think that capturing Osama bin Laden would raise the chance of hostages being taken and bombing targets to release him. However, I would see with better eyes a quick judgement than the execution of an unarmed person.
Also immagen trying to put him on trial. It would take years becuase he would be bogged down with appeals claiming that he went into court with bais against him, so therefore there would be no innocence until proven guilty. We also also spend millions of dollars moving him between a prison cell and the courthouse, because we would have to make sure terrorist don't break him out and the American vigilantes don't murder him (remember how Lee Harvey Oswald died).
On the other hand, he was just a very confused man who happened to have a lot of power. Also, his son was killed as well. It wasn't the sons' fault, his Dad gave him a biased viewpoint and he never heard both sides of the story. He probably thought he was protecting his hero father from the 'Evil American Capitalist Pigs.'
I don't think his son is as innocent as you claim. Even before his father was the world's most wanted terrorist, he supported Al Qaeda which is a group that will murder thousand of innocent civilians to advance thier religious and ideological goal. He wasn't only there to support his father as you claim.
With Osama gone, there is easily a second in command to take his place.
Osama's second in command, Ayman Al-Zawahri, is not nearly as charismatic as Osama. Many Al Qaeda leaders won't support him as the leader and he won't raise as nearly as much money for their "cause". Also, the leader of the Taliban, Mohammed Omar only supported Al Qaeda due to his personal friendship to Osama.
Bin-Laden was not truly a leader - the leadership has long been decentralised.
According to the documents taken from Osama's compound, that assumption may be wrong. Documents show that Osama has been advising Al Qaeda in both Yemen and Somalia.
