1a,
The 787s are currently being produced at a 30 million real dollar loss per frame, moving the frames from the 787 line to the 777 is where the 300 million dollar savings is for Boeing.
Boeing also has a big hole on the production line between the 777 and 777X, they are a couple of years short of orders to maintain production at the current rate. If they reduce the rate, the cost of producing them goes up.
United has also ordered I think 35 A350s, their 777s will arrive about 2 years before their A350s. Singapore Airlines has ordered 70 A350s, Cathay around 50, just about every Asian airline that currently operates 777s into Australia has ordered A350s.