1. As far as I'm concern, I don't think there is anything related (I may be wrong, still pretty new to this)
Post everything from before the page starts to load until it is done loading.
2. I'm not getting what you meant (sorry still noob), it's a site served from a raspberry pi to control my stored music by using the Pi's IP. (the program is called Mopidy)
I meant the HTML source code of the page in question, to see what it is trying to render that the standard browser can display, but the WebView can't. That part may use JavaScript - make sure that's enabled in the WebView, because by default JavaScript is turned off.