So the section in chapter 2 where you make a variety of choices will effectively alter the starting items Red has as well as her affinities and skill points (This part you won't really be able to tell of course.). Every question, including the optional ones with the other butterflies will have at least one answer that "rewards" you in some way. Of these the soul color is the most unique as each color correlates to a piece of Armor Red will start the game with, and these armors have a variety of different but useful effects.
As for time, I'm aware that it's unfortunately lead to some negative reactions from players. All I can really say is that you most definitely have enough time to safely see all the content in the demo and still take advantage of saving or bathing or other activities that can cost time. I encourage you to try and do everything!
Thanks for the feedback and compliments. I hope you continue to enjoy your time with my game!