Based on reviews I’ve watched and read its display is also exceedingly glossy, to the point that it’s questionable if it has any antiglare coating at all, which has been a major factor keeping me away. Asus should really have an antiglare option of some kind.
It is very glossy (which makes the touchscreen nice to use), but also very bright and high-contrast - personally, I have had no problems at all with readability (rather the reverse) but I don't use mine outside. It's a great display.
Not yet. As I said, I only bought it recently, and Asus have all sorts of settings in their rather good MyASUS app to mitigate this. Hopefully I won't see any problems for a couple of years at least.