1) I'm pretty sure they said that Krypton's sun was older thus the color. That's why when Jor-El is explaining that Kal-El would flourish under the younger, yellow sun.
3)Don't Know if she was necessarily stronger, but as a soldier she is more adaptable. She didn't have all of Kal's powers and couldn't fly so I wouldnt say she was stronger just more aptly suited for the situation.
Oh and also in Batman Beyond:Return of the Joker, when Tim killed The Joker Batman disowned him, so i would like to see the same thing here.
Actually he tried to get him mental help and forbade him from being Robin again due to the traumatic experience. He didn't disown him. If Bruce were to disown Damian it would have been a long time ago.