Like I said, I find 10% very low still, to be honest with you when I want a Lord dead in battle, I sometimes reload the game, not always, but sometimes I do because his death will serve me. It's not always he'll die. Mostly I let the game run it's course, maybe next battle I get them, but when I need his immediate death i do this.
You mean the lords in their 30s with few memebers on clan? I believe fixing the birth rate, marriages between AIs or NPCs will solve the problem. They're young, so a child will born quickly. And it's not always will see non combatants taking roles as party leaders, as i noticed. The clan can survive, I agree.. they should put a child there at the beggining of these games, to give a extra help.. And stopping the Clan been losted, just because the child is underage, he's alive maybe without fiefs but alive and will come to age after 5 or 8 or 10 years to fight. A clan should only be consider destroyed with all members dead.
I don't use Mods either... not at this stage of the game, i prefer waiting until the game is fully complete