2- the menus are part of the header, so combining fixed header area with a fixed on scroll menu does not quite make sense (even if everything is possible 🙂 )
But in general right now the only other fixed thing “”fixed to top on scroll is compatible with, it a regular fixed menu.
If you fix a regular area as well as use fixed to top on scroll, it would not work properly. I will look into that part.
3- If you are using the Vimeo or YouTube shortcode, read the tutorial below on how to make the text wrap around it
http://guide.weavertheme.com/additional-formatting-for-the-youtube-vimeo-shortcodes/
if you are not, you need to check if whatever you are using has the option to Float the Video container and define a right margin. if there is no option, you could use Custom CSS to do the job.
For example if I inspect your page with the browser developer tools, I see the video is in a container with the class wp-video given it is in a page with the ID 869, the rule below in the Global Custom CSS rule box would do the job
.page-id-869 .wp-video {float:left;margin-right:10px;}