"blood is reddest..."See in text(Act II - Scene I)
Red blood was a symbol of manly courage and virility. Morocco seems to be making a case for himself as a worthy suitor, even though Portia has no say in who gets to marry her.
By this Portia means much or a lot of swearing that becomes meaningless in its repetition. The rings have become symbolic for the bond between two people. In giving the "rings away to men," Portia and Nerissa's husbands have symbolically made the bond between two men more important than the bond between them and their wives. Portia and Nerissa must now use the rings to assert power over their husbands.