In answer to your questions:
1 - Yes you can make your own
child theme for Vantage if you wish. You can also buy ready-made child themes from the
AppThemes marketplace.
2 - Our themes are not designed to use a static home page (although you can use this setting in the
wp-admin), but certain links and functions may not work correctly and will require customization on your part.
3 - At this time the "Refine Search" functionality is only available via the search results in the sidebar (as seen on the
Vantage demo site), however the next major release of
Vantage v1.2 will include a sortable listings feature which will appear as a filter button below the search bar.
4 - This could be achieved with some customization, but it is not a setting in the Vantage admin dashboard.
5 - All theme support is carried out in the AppThemes forums, and your initial license purchase will include 12 months of support. Thanks.