Spoiler: show
-For the southwest part of level 4 that you can reach from below;
Notice there are two corner rooms in the area, with two doors and a pressure plate in each. The one the crab starts in fires the lightning bolts, but that isn't helpful in this case. You need to get the other one active by similar means.
Also, you will find a shortcut there soon so no need to hike back.
-For the goromorg, he likely went into the teleporter and is somewhere on level 3. You will need to track him down a get his key.
-For the plates, it is a large puzzle. You do have to throw things on them, but won't be able to from where you were standing. The cell bars will never move, but you can get around them.
Notice there are two corner rooms in the area, with two doors and a pressure plate in each. The one the crab starts in fires the lightning bolts, but that isn't helpful in this case. You need to get the other one active by similar means.
Also, you will find a shortcut there soon so no need to hike back.
-For the goromorg, he likely went into the teleporter and is somewhere on level 3. You will need to track him down a get his key.
-For the plates, it is a large puzzle. You do have to throw things on them, but won't be able to from where you were standing. The cell bars will never move, but you can get around them.