On c): recharge cycles are limited, as are Amper-hours. Idk though how much it takes, I just don't like blurs, it is like you're semi-blind or your screen is damaged, sort of. But flat interface would be too ugly without all that color blots. It is like a makeup to actually bad ui. Shame on Apple they lost it at iOS 7.
I'm not sure I accept D) as a full defense of a confusing system.
I get that some things can't be made intuitive, and have to be learned. But "there's a video somewhere if you know to look" is a crappy justification for the current setup. As is, non-regional gestures compete with regional versions of the same motion and the enabled-by-default gestures aren't terribly well chosen.
I've watched a lot of non-power-users work their touchpad, accidentally fire off either the wrong gesture or an unintended gesture, and then sort of click aimlessly until they get back to something recognizable. That's a sign that OS X is failing users, no matter how elegant things look to Apple.
b) Apple has not changed the behaviour of buttons on OSX. They still look like they always have.
c) Computing resources are not finite like oil. It's there to be used.
d) Which gestures are available has always been in the Trackpad system preference which has videos to show you how to use them.