I've been a fan of the Nexus series since owning a Nexus 4, which I unfortunately dropped on concrete a while back - destroying the screen (ouch). I now have an LG G3 which has a number of issues including cracks in the case (which are apparently normal around the mic hole) as well as audio...
If you can fight your way to the settings menu (in between closing the message) then try to clear the Launcher3 cache from Settings\Apps. Otherwise a factory reset should fix it, although you're saying you've done that - which indicates that the cache associated with Launcher3 should've been...
It's been available as an OTA update for months. In fact, when I bought my G3 about 6 months ago it auto updated itself a number of times, the final update was 5.0. The G3 is supposedly skipping 5.1 in favour of 6.0 at some point in the near future.
So you've factory reset it and during the initial setup screen your email address and password aren't being accepted?
If this is the case have you tried accessing your GMail account from another device connected to the internet?
You need to put the G3 into Download Mode before the LG Flash Tool will recognise it, check out the link below for a tutorial:
How to Enter into Download Mode on LG G3! ~ AndroidRootz.com | Source for Android Rooting, ROMS, Tricks and More!
Remote Desktop server for Android
I've done a bit of research and it would appear there are no RDP server apps for Android, only client apps that are designed for controlling a Windows / MacOS device.
The situation is as follows:
I have an Android HDMI stick (MK809-III) that I use to run Kodi...