pinboard theme mobile header issues

Here is the beta site:
https://www.worldupsidedown.com/wpnow

I have created a child theme and altered some of the css to make the nav bars less tall, as well as using a header image that is larger than the norm. While these elements look good in smaller page sizes, the mobile versions are very wonky.

For the mobile version/window:
1. How would I reduce the header image to something that would look good for this theme.
2. How could I get rid of the search form and social media buttons and put them in the mobile footer area instead? This would leave the clickable menu button only (and the reduced size header).

3. Since the normal nav bar doesn’t shrink well for mobile, how would i get rid of it. I seem to now be showing both the nav bar categories as well as the clickable menu button and the nav bar (blue) doesn’t display properly.

Thank you.