1 - Chapter 1 is all about training, so you will repair, build and expand the dojo and see the characters train and interact there.
2 - Lucy, Luna, and Kiuta's story. You will have to wait for this!
3 - In Chapter 1, there are two new, improved forests. One is dark and rocky, while the other has a river, and it's quite bright.
4 - At the end of the prologue, it is mentioned that they need the blood of Crimsonborn (or Crimson Mages like they were called before) to revert the potion's effect. The entire Chapter 1 goes around this. It is the first long-term goal the MC receives the moment chapter 1 starts.
5 - ...
6 - The marriage plot will get extended and mentioned during the rest of the chapters.
7 - There isn't another demon goddess in the MC region (Valirya). You will see lots of Demon Goddess scenes and the relationship with Narissa. The thing of Leon will have to wait a while, but you will see him.
8 - ...
9 - I have good news for you....!
10 - You will have relationships with other girls, yes.
11 - You will see lots of Sunny and her role in the Town during chapter 1, and, the new threats ofc.
12 - Done!
13 - There will be multiple guild board areas.
I hope that settles some doubts, thank you so much!