Just make such actions add relation to every adult member of that clan. It's not hard. Say you rescue a lord from a prison. You get +20 with him and +10 with his clan. Voting for a certain lord to own a castle gives +20 to the lord and +5 to the clan. Stuff like that. This way you can have more realistic relationships with NPC.2) It is a terrible idea to replace clan relationship with individual relationship. Atm you can at least build relationship with a clan by handing in captured lords to one of the clan´s holdings. With individual relationships you would basically be reduced to capture and releash (and forced to do so a truckload of times more).
"Grank is best friends with Boronchar and is generally liked by his clan."
"Grank is neutral with Abagai but her clan generally dislikes him."