The straps are, well, just to look piloty. In the real world they either hold the parachute to the pilot, or hold the pilot to the ejection seat, so I guess they would perform the same function with an X-Wing...somehow.
I keep seeing motorcycle helmets with the cheek guards on them, so I'm guessing that's where they got the idea for that. The new helmet looks much more protective, but I agree also more uncomfortable.
I am glad that the leather gaunlets and jackboots have gone away. I like the more modern look. I think it's also neat that they incorporated the ribbed sleeves from the snowspeeder jacket (and almost every other male SW jacket) into the flightsuit as well.