how about US president and entire Bush family sleeping with Saudis, would that change the perceptions?
Actually, it very much has. I don't know what you may be thinking but Saudi Arabia's standing with the American people is pretty low, as low as Pakistan's and for exactly the reasons you mentioned. The last Bush president for example, left office as one of the most unpopular president's in since they have been keeping polls. The very policies he pursued while president is why.
That is not my opinion, but it very much is the opinion of the majority of Americans.
What exactly is documented?
Everything, His identification by one of his wives. His DNA evidence, photographs, etc., etc.
http://www.bbc.com/news/world-south-asia-13313201
There are so many questions which are left unanswered like why was his body thrown in the sea and not put in front of the entire world. You dont just throw away a body without letting anyone see it after you spent billions to wage war and capture the same man?
We didn't. Numerous people saw it. OBL was given proper courtesy by a US Navy Muslim chaplain, cleaned and prepared for burial, and although buried at sea, to avoid his grave-site being an object of adulation, his body was viewed by numerous people, his DNA was checked against his sister and matched. It's all available online.
Secondly if such was the case that Osama was hiding in Pakistan, and ISI was complicit in it, how come US was in such a forgiving mood that they did not deem fit to slap sanctions on Pakistan or at the very least declare ISI a terrorist organisation?
Because I don't think ISI was. I don't think they really knew he was in Pakistan, although it was suspected, anymore than they knew about the American raid to kill him. Pakistan was not complicit in his being there. It's nothing against them. We Americans blew it when we didn't kill him much earlier in the Tora Bora mountains. He was extremely good at concealing his location. He never even left his compound and seldom came outside. We only had a couple of satellite photos of him and even then, we couldn’t be sure.