Thanks for the feedback, glad you seemed to enjoy the game.
There is not a way to increase energy past 8, and I don't think future Fairies will add this either. Though I'll know better once I'm actually in the process of adding them. The current Fairy does increase max Mood and Drive, so I suppose it would make sense in a way to have at least one Fairy help out here. Next release should have difficulty settings for Normal or Casual mode, or if players want something in between can do Custom mode and set each setting to what they like. There will be an option for instant escape where just pressing the button will get Amelia out. Until then, the other option would be to enable the Debug menu and use it to increase energy while escaping if you'd like to attempt another escape right away, or make sure you have enough for the current attempt.
Yes, Drider and Slime girls are planned to be added. Not sure about an arachnophobia mode for just one predator, but I may at some point make the game more customizable by having an option for each predator to be allowed or hidden.