1. The "Near" field is not removable via a setting in the Vantage admin dashboard, so would require some code customization on your part if you were looking to remove it. How "easy" this is, is ultimately relative to your level of coding knowledge, but there is no encryption which would prevent you from making the change.
2. Yes, you can offer all free listings if you wish.
3. The theme itself doesn't include social login integration, however you can use plugins such as the one mentioned on our
recommended plugins page, Social Login. Thanks.