i still dont test the new Version i played the 1.6 only and then dowload this game becuse, having no much time to play everthing i want, and banners in gacha games
But i will test this now having more time
1. If you're referring to the monument outside, then yes it can not be activated in the demo.
2. I'm not entirely sure what exactly you're referring to with this one. If you mean the special items that Red can wake up with then yes, you will wake up with one of the 3 special items depending on the answer you give in chapter 2 to a particular question.
3. The medicine quest can not be fully completed until chapter 7. So in the demo you can only get as far as making it and then finding the man has vanished.