I played the demo up to Falgar's defeat. After his defeat, there's a lot of content I haven't seen yet; I just didn't post it because I was simply too lazy.
1. Several characters joined our group, and none of them transformed into piercings. In some sex cutscenes, Reyn undergoes some temporary mutations.
2. There are plenty of places to spend money; there are many good weapons and armor from future vendors. And I advise buying plenty of ELIXIR; it will save the characters' lives.
3. Falgar is quite ambitious; he destroys a city and builds a grand empire in the clouds. He's a very imposing villain with a majestic trajectory, but I confess that the fight against him was easy because my group was very strong.