Intro & Heeeeelp !! :)

Hi Guys, I'm Stu. I run www.dragonuav.co.uk an aerial photo & video business and have done a lot of work on my website myself, with the bones being laid down (and the odd rescue!) by a Dev friend.

I am nearly there, but have some tweaks I need to get it how I would like.

1) My site hosts an Aerial tour of Wales (UK!) using 360 panoramas hosted on roundme.
http://dragonuav.co.uk/aerial-tour-of-wales/
I have embedded the tour, and set the backing music to play from YouTube in the background. but the sizing ! I have tried many things, but my lack of knowledge in terms of inputting/translating general wordpress advice into Divi is leaving me short. The embed doesn't size to full screen responsiveness on any device and never seems quite right on any device. I have tried getting the "intrinsic-container" method to work, but just cant get the CSS part going. Could anyone PLEASE point me in the right direction? I would like it to be full screen on any screen.

2) As mentioned I have the music embedded ok, but would like to make it optional, by way of a simple play/pause button overlaid on the Panos, always on top.. I have gone through many plugins but none quite seems to do what I want.