SHOPIFY - Separate Fallback image for Mobile devices, Activate Full Screen Button & Mainpage top black ribbon problem.

Hi, this is Saif. On my website([login to view URL]) I need following 3 small issues be resolved, in a timely manner; 1. Need 2 different images The Fallback image, which appears before auto-play video loads. Currently same image is appearing for PC & Mobiles. That's why, the very image is appearing cut from sides on Mobile Interface. 2. Need to activate inactive "full screen button" on auto-play video, so that it may enable to view auto-play video in full screen in mobile interface. 3. Black ribbon on top of auto-play video some disappears, which its intended. But some times while scrolling back to auto-play video the black ribbon doesn't disappear and sometime, there occurs mess-up of black ribbon's symbols while scrolling back from back to top(auto-play video).