Few Issues – Please Help

First off the website is http://www.autoyard.com.au

Issues:

1/ when on a listing page (so viewing a vehicle) I have added a contact seller button, but when you try and complete it, it says “Please complete all fields” and wont do anything else.

2/ Main Page, Still getting City Cars on 3 of the icons and have tried fixing but having no luck.

3/How do i set everything to Australia as default. So when customers sign up they are automatically in Australia as the default location no Afghanistan

4/ How do i ad more options to vehicle details?

Thanks