obtener datos que no estan en una tabla

[quimfv]

Uff, dificil de seguirte, pero

Código:

SELECT recruiters.first_name, 
       recruiters.last_name, 
       talents.fr_id, 
       talents_events.talent_id, 
       talents_events.event_id, 
       events.description, 
       management.fr_id AS agent_frid
FROM recruiters JOIN talents 
          ON talents.prereg_id = recruiters.id
	         JOIN talents_events 
          ON talents_events.talent_id = recruiters.id
	        JOIN EVENTS 
          ON events.id = talents_events.event_id
		JOIN events_locations_agents 
          ON events_locations_agents.event_id = events.id
		JOIN management 
          ON management.id = events_locations_agents.agent_fr_id
		JOIN users 
          ON users.id = management.user_id
WHERE recruiters.id = talents_events.talent_id
  AND talents_events.complete =1
  AND events.id NOT
	IN (SELECT event_id
		FROM comments)
  AND talents_events.talent_id NOT
	IN (SELECT talent_id
		FROM comments)
  AND users.level =2

Las condiciones en rojo son redundantes, puedes eliminar la del where.

Luego intenta esto:

Código:

SELECT recruiters.first_name, 
       recruiters.last_name, 
       talents.fr_id, 
       talents_events.talent_id, 
       talents_events.event_id, 
       events.description, 
       management.fr_id AS agent_frid
FROM recruiters JOIN talents 
          ON talents.prereg_id = recruiters.id
	         JOIN talents_events 
          ON talents_events.talent_id = recruiters.id
	        JOIN EVENTS 
          ON events.id = talents_events.event_id
		JOIN events_locations_agents 
          ON events_locations_agents.event_id = events.id
		JOIN management 
          ON management.id = events_locations_agents.agent_fr_id
		JOIN users 
          ON users.id = management.user_id
WHERE talents_events.complete =1
   AND users.level =2  
   AND (events.id NOT
	          IN (SELECT event_id
                		FROM comments)
            OR talents_events.talent_id NOT
                  IN (SELECT talent_id
                 		FROM comments)) 

No estoy seguro de si he interpretado bien lo que necesitas pero por intentarlo no perderas nada.

Quim