To address your concerns about not being able to access the support forums, the answer is really neither of your suggested reasons. The reality is that we do have to deal with situations where individuals have obtained our themes without actually purchasing them from us, and then seek to also gain free support which our customers actually pay for. In fairness to our paying customers, we felt this was the best way to ensure that they're essentially not left paying for something that others are not.
Ok, so the Vantage .csv import function basically allows you to import data in the form of a .csv format file for importing by default: (title, description, author, date, slug, status, address, phone, facebook, twitter, website, listing_category, listing_tag, lat, lng.) - If you'd like to import more than this, we have some documentation here
which explains how you can customize the importer. as a developer you may find this developer documentation
part of our site useful also. Thanks.