You are not required to have any paid plugins when using IMPress Listings. The IDX Broker import feature (requires a paid IDX Broker account) for IMPress Listings will only import data for which the IDX Broker API returns, which is not all the fields that get displayed on the IDX Broker detail pages. All we can do about this is request IDX Broker to update the API to return all fields.
If the issue is they are in WordPress but not displaying on the front of your site, it might be a conflict issue with your theme. If this is the case you can copy the template file to your theme and modify the design and what gets displayed.
Further Reading:
- IDX Broker API - Featured Properties