Your thread is been moved to our EPO section, you will be assisted by our experts here soon.
If the item is not available to be added then its probably not collected by the Agent as one of the properties.
To answer the second part of your question, try editing the query you created from the ePO console and switch to the Filter page. On the left side add the property you want to filter on by clicking >
Select from the drop down 'value is not blank'. You can click + and add other properties to the list to further filter it.