Just a few thoughts that came to mind when reading about how the succesion system will work.

For starters if female children are married off will female children of the A.I. nations be seeking the players male children's hand in marriage? And if so are A.I. nations able to inherit kingdoms as the player can?

Also I was wondering how everyone feels about heir deaths, because to me it doesn't make that much sense that out heirs would be indestructable. Also I thought a good addition to the dynasty system would be that after conquering a enemy city you would be given the option to execute any of the heirs and heiresses of your rival nations. Obviously doing so would carry with it morale penalties to the city and enourmos penalties with the nation of the heir or heiress. The opposite of doing so would be ransoming them off. The point in killing them would be both to deny the rival nation the power of their hero characters but to also stop any claims to the throne

I can think of several times throughout history where just such a circumstance arose and how it impacted the outcome of the war such as the Greeks killing Hectors son or Ceasar Agustus killing his half brother. 

Please give your own opinion on the subject.