how to pause the game

Yes, I've done this. That is how I found out that using Cortana makes your game go into it's pause menu. Using the Xbox voice command doesn't pause your game, but you can not use the Xbox voice command over the headset. Perhaps if they could just make
it so the Cortana command did not pause the game? That, I think, would solve the problem.

No it wont hurt anything. The instant resume feature is great but does work better with some games than others. Nothing better than just picking up the controller and gaming from where you were stood/crouched/hiding the night before!

I love that feature but with dragon age I don't like that the playtime clock kept running even when my machine was off

One thing to note is not all games get on well with this practice, I had issues with Sunset Overdrive so make sure your game is saved before putting it in low power mode to be on the safe side.

^if you press it and hold it for 2O seconds while holding a zippo to the corner of your carpet then the answer is yes (maybe not the explode bit)