There are some cannon elements, where your previous decision won't matter (Ari is alive), but you don't need to own the previous copy to my understanding. You'll have to confirm your choices here, so eg if you want to have a different playthrough for your prior game, you won't need to play it all again, you can just change it by giving different answers in this game.
At least, that is my understanding. I understand why you wouldn't want to play the demo, the wait is killing me too :D But it is only a few more days, so chin up!
Viewing post in [MAJOR SPOILERS] Does choices from Demon heart matter?
Oh yeah, I couldn't defeat game without killing Ari, each time I would get tortured and the game would end. I don't mine that choice not happening XD. The only ending I havent done is the romance of Ari and I just don't have it in me to replay 3rd time cos even with skipping dialogues it is slow just to get to the part with her and the other characters always dares me to romance them XD
so glad that some choices carry over then. :) thanks. I will try and wait patiently for steam release.