besides wildbull is there any events that can cause you to lose a girl?
I don't think there is, at least in the demo.
Hell, I took a peek at the game files out of curiosity, and Wildbull seems to be the only one who can enslave your teammates.
As for me, I've made good progress, but encountered a couple of blocks: one, I don't have a "Time Switch", so can't access the block puzzle in the snowy warehouse. The dungeon where the time switch was acquired in the previous demo is impassable due to an immovable block (the block is right up against a wall and there's nowhere to push it).
Two, the "Volcano" area currently crashes the game upon entering.
Three, the Roper Nest below the Barbarians' camp is glitched the hell out with its graphics; upon getting into a fight, just get blank white screen (not technically crashing, though: sound effects and music still go on, suggesting the game is running).
Currently trying to puzzle out the Imp quest in the snowy mine as well as one section of the sewers I can't figure out how to get into. Also, there's a dragon on the mountaintop, but he's really strong.