1. You're correct, the contact information field and some others are not configurable from the custom form, so this section would require customization of the default theme files if you're looking to make changes there.
2. If listings are completely free, then any fields and redirection relating to the payment process is automatically not included.
3. The demo site is already logged in by default, and although it is a fully functioning demo, it does not save data which is why you cannot complete listing and registration steps. On a standard installation they can simply use the register link at the top of the page, or when prompted (if they try and place a listing).
4. Searching, by default, is more general in terms of city or country on the main index page, but within a location search results page you will then see the "Refine Search" functionality in the sidebar which allows you to narrow it down a little further, as seen on the
Vantage demo site. Thanks.