Being a game designer myself, I feel what you going through. Designing puzzles is a tough challenge, but adjusting them to player's expectations and skills afterward is even harder. Especially when you have such an intricately interconnected system as your game world. But that's that major source of fun in our craft, isn't it? ;)
I think caterpillar actually works well at signposting the exit! And increasing its collision box might work well too.