Just left our '15 at our local dealer. Was able to talk to the mechanic we use. He won mechanic of the year a few years back out of all Nissan mechanics tested. I trust him. As far as the p/s fluid he said as long as the level touches the dip stick (my words, not his) the level is okay. Reason, steering is electric not like our old pump variety, though there must be a pump somewhere. He did say he adds a little just to make customers feel better.
As a side, my wife who drives the M 95% of the time said there has been a bump she feels through the steering wheel every morning. As I saw in another thread, Greg said it is the hydraulic motor mount and that bump (clunk) is normal. He will find the service notice for us.
I will let you know if he finds anything else tomorrow. It is just nice having someone who knows what he is talking about. Not that any of you don't, but Nissan tested.