I agree with everything you said. Nice head on your shoulders there 
I still think the leaving penalty for a “casual” game mode is a severe overstep, and will end up causing way more harm than good.
But it depends on your point of view. New players will probably be more likely to turn away from the game because of it, while veteran players will probably see some benefit from it, even if its slight. Which side is better to cater to grow the game though? And an underlying point, did qp really need this at all?