Thanks alkis21!!
1. The Banshee door opened when you solved the symbols puzzle and stopped the demonic liquid from flowing.
Yeah makes sense... though they should have given some indication that turning off the snot had this side effect. I tried opening the door again only out of frustration, cause I was stuck, and was very much surprised to find out that it's now suddenly open!
2. It was written in the Vampyre guide.
This one baffled me the most... now I saw it in the book (page 2 I think). So I guess conversation-topics about the black cloth were added after I read the book?
3. Apparently the gypsy was possessed by Shrowdy.
I meant BEFORE Shrowdy entered her... I think she was talking to the two vampire hunters, not sure though, and definitely not sure what she was on about when she talked to them. Lack of subtitles in videos is a problem.