Yvcomment use the articles table (jos_content) with a dedicated section and category
This is the structure:
id title alias title_alias introtext fulltext state sectionid mask catid created created_by created_by_alias modified modified_by checked_out checked_out_time publish_up publish_down images urls attribs version parentid ordering metakey metadesc access hits metadata
so, id is id
in your import wizard you have a combo call "Commented component value (obligatory)" with some value that I don't understand, I chose com_content (but tried different values too)
when I click preview I obtain this message "Id column is obligatory ! Please, select the column."