In the Masteries when asking to get all scrolls, shouldn't the Gems requirments be relative to the amount of scrolls needed to unlock the champions final masteries?  

example: If a champion had half the scrolls already, and only require Red Scrolls to unlock all Masteries, The Gems needed to get all Gems could be 400 not the full amount of 800 for half the amount of scrolls needed. 

Maybe?

This would be nice to see but I dont see them making the change. 

Were you asking about Campaign Ultra Nightmare?  I can ask but I dont believe there are any plans for that.