You understanding of Saudi Arabia, as with most people, is very limited, it appears, based on the statement you just made.
Saudi Arabia and Bin Laden are not one in the same. Blaming Saudi Arabia for Bin Laden and the trade towers is like blaming the US government for Anarchist gang bangers.
I will, however, strongly disagree with giving Saudi Arabia ANYTHING. My reasons are based on more than just news media. Saudis are completely worthless and useless. They already have billions of dollars worth of military weapons etc, and they just all sit their in warehouses because they know what they are worth and refuse to use them. I am sure they hope to sell them or Trade them some day when they "feel" it's necessary. They refuse to fight for their country at all, they refuse to defend their citizens, and they are cowards. Their word cannot be trusted either.
This is nothing more than a political stunt. I am not sure what exactly Trump hopes to gain from this, but I can assure you, it's probably not worth it even IF we can get them to cooperate.