With all the deaths that have happened and continue to occur, it seems strange that Julia, who sees ghosts, hasn't seen any for a while. One would expect restless spirits to abound, some eager to aid the teens for revenge. The lack becomes pointedly evident when Ivan calls Julia "Ghostbuster" for no functional reason.
One or two nosebleeds alone do not an epidemic make.
It's unclear where Soldier Torres hangs out. He's from the enemy camp yet he's allowed to wander around the school unchecked. It mostly seems the script writers don't know what to do with him.
Where does Ivan get handcuffs?