For me, yes.
Better camera (on par with the gs 7 for photos imo), screen (anandtech rate it as one of the best especially for calibration), fingerprint scanner EDIT: Also fast charging which is great, iirc, only beaten by the one plus 3...
The performance is good especially with nougat. Battery life is about what you expect, you will need to charge every day or 2 like most phones and the speaker isn't exactly great but it is front facing which is a nice bonus.
Design is ok and build is good, better than the n5 overall imo.
My main complaint with the 5x is the vibration motor, it really is crap.
The only other phone I would look at today is the one plus 3, I would probably even take it over a gs 7 tbh, more stock android + lots of nice tweaks and updates can't be any worse than Samsung...
No idea about number 2 and for number 3, I will be shocked if the nexus 5x doesn't get the next big android update...