I think ( if this is what your asking ) to get across the leach pond you need to make the stilts. If thats not what your talking about please be a little more specific, or try someone else. I hope this helps thanks for asking.
For the loose stairs I know after you swing from the grappling hook and land on them you automaticly need to jump forward. If there is a huge gap and the hook cant reach go as far as you can and try. (which you probobly already have) Mabey there is a door that you've passed by or somthing. I hope I helped.
I think what your trying to find is the spring. the spring is located in the grandfather clock in the main room next to the fire place. open it and then click on the clock and you would find it.
I hope this helps Good Luck!