1. Will Japan be added?
I have no plans to add Japan. It would entail expansion of the base map, which is something I'm technically unable to do. It would also mean spending long months on researching the title holders and with the amount of work on the plate that's something I'm unlike to undertake any time soon.

2. Will Korea be added?
Yes, hopefully together with Southeast Asia soon.

3. Which DLC are necessary?
Jade Dragon is necessary for events to fire. To play as Taoist you need either Rajas of India or Jade Dragon.

4. Will Grace Interactions be readded?
Some, if not all, of them will be readded in a different form.

5. Why Balhae and not Bohai?
I was torn here. Generally the modern Korean rendering of the name is becoming increasingly common in the western academia. At the same time Balhae is closer to the reconstructed Northern Chinese dialect of Middle Chinese than modern Mandarin Bohai is. At some point I might try to make a Middle Chinese localisation, which hopefully will make all sides happy.

6. Why Balhae owns whole Liaodong?
I couldn't find a source which stated that the entirety of Liaodong was taken over by Balhae, not even when Liaoyang itself was. The region doesn't figure at all in 新唐書，舊唐書，資治通鑑. 遼史 also doesn't mention when Khitans conquered the region, at some point it just appears in Khitan possession. I've read opinions that it became a no-man's land, independent from Chang'an, Bohai and Khitan, but as the records are non-existent I decided to take the easiest route and just gave it to Bohai.