The plugs look a little too clean. The inside is still very white. You are not running rich, that's for sure. Try a video with it in neutral. Step up the idle slow and then up to running RPM. I'm trying to rule out anything outside of the engine. Your video almost sounds like someone was blocking the exhaust or the engine brake was coming on when it shouldn't. Might even be the fuel pump acting up too. It is very hard for me to tell you what is wrong not being there and touching the machine. I know it's a pain to bring it to the dealer, but if you can't find the problem soon, your best bet will be them.