Ok so I've played this for a little while now and i have a few suggestions to make based on my understanding of the story, both from the books and the games. I've played the two games and read the first two books so that's what im basing my info on. I don't know how much you're basing this off each of them so i apologize if im correcting you for something that happens later on.
1) Foltest's Titles: His official titles are King of Temeria, Sodden, Pontar and Mahakam as well as Senior Protector of Brugge, so i feel his CK2 titels should reflect that. I don't know what the borders of Pontar are supposed to be but i think giving it the duchies of Dorndal and Murivel would probably work, or even just Dorndal. Brugge probably doesnt merit its own kingdom, but giving Foltest the duchy title would cover that.
2) Adda's Inheritence status: Adda was legitimized by Foltest, whereas Anais and Bussy were not legitimized as far as I know. Foltest even gloats at one point that Radovid won't be King of Temeria because the nobles won't accept a foreigner on the throne, suggesting that otherwise she would have ruled.
3) The Emperor of Nilfgaard: In Blood of Elves he is described as quite young and unmarried. Since i've only read to the second book my information could be dated here, but my impression was that the games take place not too long after the books, relatively speaking.
4) Dol Blathanna: In the books somewhere they say that Dol Blathanna is under the protection of Nilfgaard, so it seems to me they should be a vassal of theirs. Again this could be dated.
5) Kaer Morhen: Shouldn't the Witchers own Kaer Morhen? Even if the only holding in the county is the castle i feel that they should own it. Speaking of Witchers, shouldn't Vesemir still be alive? I didnt see him on the list of witchers.
6) The Order of the Flaming Rose: I'm not totally sure about this but I believe Radovid was in the process of seizing the Orders holdings in Redania and Seigfried takes over the Order in Temeria and recreates the Order of the White Rose.
Aside from that I had a few questions about your plans for this. Do you plan to incorporate anything involving the terrorist organizations such as the Scoitael or the Salamanders? You could do something like the Byzantine Greek Fire event chain where you can choose to fight them or negotiate.
That's all i have to say. I hope you'll take this into consideration with this long overdue mod
1) Foltest's Titles: His official titles are King of Temeria, Sodden, Pontar and Mahakam as well as Senior Protector of Brugge, so i feel his CK2 titels should reflect that. I don't know what the borders of Pontar are supposed to be but i think giving it the duchies of Dorndal and Murivel would probably work, or even just Dorndal. Brugge probably doesnt merit its own kingdom, but giving Foltest the duchy title would cover that.
2) Adda's Inheritence status: Adda was legitimized by Foltest, whereas Anais and Bussy were not legitimized as far as I know. Foltest even gloats at one point that Radovid won't be King of Temeria because the nobles won't accept a foreigner on the throne, suggesting that otherwise she would have ruled.
3) The Emperor of Nilfgaard: In Blood of Elves he is described as quite young and unmarried. Since i've only read to the second book my information could be dated here, but my impression was that the games take place not too long after the books, relatively speaking.
4) Dol Blathanna: In the books somewhere they say that Dol Blathanna is under the protection of Nilfgaard, so it seems to me they should be a vassal of theirs. Again this could be dated.
5) Kaer Morhen: Shouldn't the Witchers own Kaer Morhen? Even if the only holding in the county is the castle i feel that they should own it. Speaking of Witchers, shouldn't Vesemir still be alive? I didnt see him on the list of witchers.
6) The Order of the Flaming Rose: I'm not totally sure about this but I believe Radovid was in the process of seizing the Orders holdings in Redania and Seigfried takes over the Order in Temeria and recreates the Order of the White Rose.
Aside from that I had a few questions about your plans for this. Do you plan to incorporate anything involving the terrorist organizations such as the Scoitael or the Salamanders? You could do something like the Byzantine Greek Fire event chain where you can choose to fight them or negotiate.
That's all i have to say. I hope you'll take this into consideration with this long overdue mod