What possible reason would there be that the flamequencher not work on the flaming cage keyhole. I click the use but it won't acknowledge it???

on somethings that require you to use an object you have to get real close or it will not work. just one of the few bugs in this fine game.

emmm...when you first enter rapaz area, did you turn left and saw this huge lava monsters walking?

Welcome A-Board, Dr. W.
For the hard-to-hit keyholes, and other things needing items, you can wave your pointer around empty to see where it becomes a hand, then get the item into the same place.

No need to turn left.
You'll see it also if you come from the other side, and have a far better view.