Your question is indeed interesting and one that is often faced by many start up businesses or even those that have been online for a while.
First and foremost, a website is your shop window. This needs to be looking and working the best and if it is not rendering correctly, errors with coding etc, easy navigation and further more not UX (user experience) than it is indeed going to cause issues. These would be for the user/visitor as well as google.
Before one starts throwing money at google adwords, advertising etc, make sure your front end loves your back end (your front of the website with the back server, hosting, usability etc) and vice versa. Does not matter how much money you invest, if these are not working then money is just being lost in a dark hole.
I see you have a few issues with the website from loading, navigation, issues rendering with different browsers.
The next is content and also the SEO and then SEA. These two work hand in hand as well.
Initial small steps with ensuring the above is correct will help grow a stronger and more stable online business, or foundations are solid, helps to build a stronger and stable building! (same for the web)