Most of the times some info is missing on the header. Take a look at this interesting article http://www.bigbossmas.com/web-development/responsive-web-design-designing-a-website-for-mobile-devices/
Contacting the theme developer is always the starting point. Did you already tried that?
Your page is showing a Script error on Chrome Console. There are at least 2
<p></p> tags messing with the jQuery document ready function. This might be the origin of your error.
Without a link to a sample page I think nobody will be able to help you… Including me
Try deactivating all the plugins and selecting another theme and then re-select the current one.
There’s no big secret. Just spread the links wherever you can and if they have images associated make sure they are attractive. Using Google Adwords might also be a good investment.
What are the usual syntax errors? Paste them here…