Kingroot uses its own root management system and won't let you use supersu with out jumping through hoop. This happened to me. I flashed a custom rom that had supersu builr in to fix. Or you can try this https://play.google.com/store/apps/details?id=darkslide.com.supersumepro can't say if it works or not.
https://play.google.com/store/apps/details?id=com.jrummy.apps.build.prop.editor
But be very careful. You can easily bork your device editing the wrong thing so make sure you backup before poking around in there
Get a chromecast, thats really your only option. The quality wont be perfect either if you have in screencast mode. It really depends on the device you use on it. I havent tried my G-pad with it but it should work fairly well.
http://www.howtogeek.com/199654/play-your-android-games-and-videos-on-the-tv-with-google-chromecast/
EDIT: Rewrote my response plus added a link to help explain better
If you have confirmed that this site is fraudulent, and you want to help protect our community of LG Gpad 7 users (which will ultimately help you, when our community attracts more DEVs), then I'd suggest you participate in rating this website here (as I did): https://www.mywot.com/en/scorecard/50lollipop.org
Its a micro usb to hdmi cable that you plug from the charger port to your tv's hdmi port to mirror the screen. Heres the link to it on amazon, sorry this isnt typed better or hyperlinked, im on mobile right now.
http://www.amazon.com/gp/product/B00EPMF504/ref=od_aui_detailpages00?ie=UTF8&psc=1
I really, truly wanted a good first experience with Android. I've not lost all hope, this just happens to be a bad example of what the OS can do. At this point, I have a few options: -Wait for the LG G Pad to get upgraded to Lollipop 5.1 -Find a temporary fix for the tablet (Xposed, revert to KitKat) -Get a new tablet
None of these are particularly great options. :( Do you have any opinions on this particular tool? https://play.google.com/store/apps/details?id=com.thetonyp.fixlollipopmemoryleak&hl=en