Hey Luzcypher,
I want to thank you for that initiative regarding scammers karaoke singers and stuff. It is a well needed improvement.  I appreciate it very much, my problem with it is the exceptions. First of all you are quoting this to be an exception:
https://www.youtube.com/watch?time_continue=3&v=5wGllhz2S-M
Well, to me, I can't tell whether it is sung live or not. Whether it is just a playback or a full multi track recording. In the end of her performance you can hear something that's sounding different and I guess this is the "true" voice while the rest is playback and lip sync, however, I will consider it arbitrary in comparison to other "karaoke" stuff, to include this as an exception and  exclude other similar karaokes from openmic.
I guess a karaoke in the way of the above mentioned link must be with no doubt the live performance of the entrant, which is not clear in this example.
On the other hand, you state, that there has to be instruments played. What about a a-capella group would performing live for openmic like my friend @brudaj with his vocal group 
https://www.youtube.com/watch?v=vGoP9bEYuh4 
would it be excluded or another kind of exception?
Perhaps you see the point I want to make.
This is a huge contest and I thank you a lot for all and what it means to me, but there has to be some continous and transparent interpretation of the rules in order to not pique others. I would be pleased to see it that way therefore it can continue to be as great as ever still issuing the scammer-thing without favouring one against others unsjustly by a intransparent censorship. Thanks for your time reading and thanks for all your effort, time and work!!!