There is a big difference between thinking you're doing the right thing and actually doing the right thing.

But who knows what is 'the right thing' ?

I believe the right thing consists of:
1. trying to limit and lessen hurting of all human beings(physical/psychological/em otional) as much as is possible.
2. in the context of decision-makeing, I believe 'doing the right thing' is making decisions based on facts and rational thinking while not letting emotions, subjective experience and faith (wether religious or ideology) get in the way of your thinking.
3. Not discriminating any group (gender/age/race/faith) because of some irrational (mostly undefendable in face of reason and questioning) reason, or because of your faith.

So given this definition (suggestions and constructive criticism is much appreciated) is Osama bin Laden doing the right thing ?

Q. Is Osama bin Laden trying to limit and lessen hurting as described above ?
A. No, it does not seem like he is looking at the facts of his acts.

Q. Is Osama bin Laden basing his decisions on logic and facts ?
A. No, it seems like he is basing his decisions on his faith and/or ideology and emotions.

Q. Is Osama bin Laden makeing sure he doesn't discriminate any group ?
A. No. He is deliberately discriminating women and people of no faith or other faiths.

So is Osama bin Laden doing the right thing ?
No. Given my definition, he is absolutely not doing the right thing.