"Laguna is forced to fight five battles on the cliff, but tampering with the middle trap door, blowing up the two detonators in the correct order, and pushing the boulder will each prevent one fight."
Randomly found this while cleaning my room and searching for game notes I typed out "back in the day".
I remember when I first heard this, I knew I could do all those things but I didn't get the connection with the last fight of the area.
I'm also pretty sure that picking up the keys that fall out of your pocket will actually create items for Squall's trip later.