1 - Yeah, that was a glitch that I found when adding a new passive in the next update (So what I assume happened was that you did the spare the Man in Red quest to get Leon's passive which decreases 2% of MP every turn, but I found that I made it affect the whole party).
2- Thanks for telling me that, I will have that fixed in the next update when the final boss for chapter 2 is released!
3 - Two of them were meant to be solid, but due to the way RPG Maker water works, one of them is meant to be not solid (The spinning one in the corner)
4- At first I didn't see what you meant, but I found it and will have it fixed next update!
5- No you were not meant to be able to accept both quests. It would appear that I accidentally set the shinning lady's condition to the wrong switch (Basically hidden variable that is on or off) which made it so she didn't care that you sided with the other guy first. I will add a debug fix to the crystal next update so you won't have to restart your save as I am sure that other people did that too!