PDAnet302 for android to root with Kingo on PC
Two years ago I downloaded PDAnet302 for android on my PC to root my Galaxy Nexus - that was the missing ingredient for me.
I believe its possibly the answer for all of y'all too. Download it on your PC, plug your phone in and it'll connect.
I have the MJE Note 3 and was able to root my phone using Kingo first try. My note 3 connected to that old software "PDAnet302" on its own - I had forgot it was still on my PC from 2012.
Hope this helps, BTW I only read five pages of this thread. Sorry if it was already mentioned.