Okay firstly...
I don't believe people are still talking about it.
Next,
Well, from what I understand, the members from Al-Qaeda believe that they are dying a noble death for the sake of religion. This is called jihad. And in Islam, those who died for the sake of religion would go to heaven. So, the members think that they are doing something right. They certainly have no or little idea that they are doing wrong but then again, you have to look at both sides of the story to know the entire perspective.
Thirdly,
I'm not so sure about that. Quite a lot of people believe that what he is doing is right as you have to remember that Muslims and the Americans have a VERY strained relationship. Currently, with America's power and influence, they might just say that they will kill him but we have no idea what they truly feel.
Personally, I don't disagree with Osama. But I don't like his methods. He is trying to do everything in the name of Islam but I think he forgot that he could do it through peaceful negotiations but then again, religion is a very complex issue. People will die for religion therefore, they might go a bit to extreme.
And just becaused he killed, he have to be killed? Since when is that anyone's right to judge if he should die. Everyone will die in their own time and that's God's will. He is the only one who can choose who dies or not. This is one of the many reasons I hate court. Humans are the ones who pass judgement and humans by nature, are greedy creatures, easily bought over.
True, he has killed but killing him will just add one more body to the count. Al-Qaeda won't take his death lightly either hence, more killings. This kind of chain reaction is not going to stop. Even if Al-Qaeda is destroyed, others could follow in their footsteps.