In answer to your questions:
1. Yes you most definitely can change the language for our themes :) Our
languages page shows how this is done. At this time I believe there are Croatian language files already available for all themes apart from Quality control.
2. You can search the highest rated from within your search results, as you can see here on the
vantage demo in the "refine search" sidebar there is a "Highest Rating" option. This is not a search found on the main page though, so it would require some customization of the default theme if you wanted to add such a function.
3. The built in .csv importer can be found here on the
Vantage admin demo, although this is primarily for the listings themselves.
4. The default URL structure is e.g.:
and does not specifically include the location. Unless the category itself was the location, then no this would not be how it appears on a standard installation. This too would require additional customization. Thanks.