The LED is in the lower right hand side of the monitor. If your viewing perspective is too high, it's easy to miss. It should be white in desktop applications, red when GSYNC is active, green when 3DVisison is enabled etc.
I don't know if Asus has any plans, but there is a known Phillips display slated for release with that size/res.http://www.engadget.com/2014/01/06/philips-27-inch-monitor-nvidia-g-sync/
I understand your frustration. I don't work for Asus, so I can't help you there. I can however wholeheartedly confirm that Asus' handling of this display's launch, and apparently its release as well, has been a travesty. If its any consolation, it's...
I can confirm having this issue as well. I don't know if this is coincidence or not, but the manifestation of the Out of Range error coincided with the GSync indicator LED not changing to red while in game. Reseating the cable restored LED functional...