what to do while collecting beans?

No, to be honest, I didn't do anything with it either. What I did is simply look around for other key items. I believe there is a passage way somewhere in the great hall. Its been a while since I played, however, I beat the entire game, so if you need help just let me know. What tripped me up was the "Spider" level where you go into the forest and you have to beat the many spiders that lurk around, but you don't seem that far ahead so I'm getting too far into it. I hope this helps with the knowledge of a secret passage way. If not, I can go back into the game and try to help you out more: Hopefully I still remember!