1."Will Jung So Min be a part of part 2?"
Yes. But she will be shown in a flashback or how she was rescued.
2."Why is Jang Uk using Naksu's sword?"
Probably because it is the only thing she left behind for him.
3."Who rescued Mu Deok?"
Jin family or some unknown organization of Soul Shifters
4."How does Go Yoon Jung appear again when her body was burned?"
Magic, Buyeon's divine power or ice stone's power
5."I've a question about who sits on the throne before the entertainers in the preview. Looked a bit like the queen/shaman?"
Maybe there was some festival or something and I guess it was the King and Queen
6."Do you think the 1 episode of part 2 is going to start immediately after the end of part 1 or will there be a time skipp?"
I think they will show the time skip timeline first and then they will show the flashback of part 1 a little bit.
7."Is Jang Uk searching for and killing all other soul shifter as a penance or is He only searching for Naksu?"
I believe he is still looking for Naksu and trying to find out what exactly happened that day. And he is killing soul shifters because he is a mage and just like how he used to kill them, the only difference is that he is quite merciless now.
Now my questions are:
8."What do you think happened to Mu Deok / Jin Bu-yeon and also what happened to her body? Is she dead or is she in a coma?"
9."Will Naksu lose her memories?"
10."Will it be a happy ending or sad ending?" :''')