Re: Duarte, the Android UI guy (laugh)
"Sorry Mr. Duarte, I'm totally unimpressed with the work you have done in the past years." ... "Recently changed from Lumia 920 Windows Phone to LG G4 Android phone."..."Double-layer homescreen (one with all apps, one with selected app)."
I hate to be the one to point this out, but you're not looking at Duarte's work. You're looking at an LG designers work. Duarte works on stock Android (as in AOSP), if you want to experience his work, you'll need to replace that LG launcher with the Google Now Launcher (available in the Play Store).
As for whatever is going on in your notification drawer, I can't comment as I haven't seen it, and there's not a lot you can do about that as that is part of the core OS and if LG have messed with it, the only way out is to flash a custom ROM. I can say on a Nexus, if you get a notification, it's clearly there in the notification draw.