We use WordPress standard database structure – https://codex.wordpress.org/Database_Description
If you add the properties in the WP database – they will exist in Admin – Properties and all the features designed in the theme will work.
For import – there is a WP ALL IMPORT topic here that may help – http://wpestate.org/forums/topic/wp-all-import-google-maps/
Also – for fast replies please use our client support system here – http://support.wpestate.org/ We cannot answer on forums daily. This is just a tool to share publicly information we consider useful to other clients.