Sorry, that's not even close to constructive. If you want it to be the malicious interference of a cruel villain you need to involve it more in the game. Any time it thwarts or subverts the players efforts it should be accopanied by a clear indication that that's what's going on. It doesn't necessarily need to be as blunt as an appearance or a speech but it has to be apparent.
As it stands we were all completely unaware that it was an omnipresent villain at work and, as a result, wrote it off as being a string of near game-breaking errors. We've all played our fair share of awful levels round here and if you're going to use some of the gameplay elements that crop up in those sort of levels it's a good idea to make it clear that you know what you're doing and there's a good reason for it.
Oh yes, and with the banishment cave.. I know you've got the ghost who says it's worthless to even try getting out you've set up an apparent exit that appears similar to a challenging section of game. People have preconceptions about how a game works and while it's possible to subvert those expectations to good effect it needs to be a constant. If you only go with odd appearances of it wrapped up in a very normal-looking game people aren't going to approach it in the right way and they'll mistake it for an error.
Many games have got brief moments in a similar situation but it's always a small enough area that the player can try every possibility for escape, notice it's useless and then wait for the cutscene or event that'll progress the story. People become accustomed to being the driving force that moves the story forward and tend to be very slow to realise when you've changed that.
But this is only my second level ever made. Not as an excuse to be lazy, but things are bound to be messed up or broken. I'm entirely new to this.
For the banishment cave, here's what i propose...
-It could look like a dead end. If the player know that he is cornered, he'll then start to search for a secret passage.
-The ghost could say that "there might be a way out but he stopped searching for it"
-The detector could be an item you don't lose or get back in the cave. Then you make a signal showing the exit.
or
-Since you keep the eye, use it to show the exit.
or
-find a way to remove the eye and open the exit that way.
Here's what I've done using some of my own propositions : link (http://knyttlevels.com/levels/Numberplay%20-%20A%20Hero%27s%20Tale%20%27cave%27.knytt.bin)
This isn't really hard but at least it's not impossible to guess.
EDIT : oops, i copied your intro and did not remove it afterward.
The final version of this level will be finished by Christmas. Thank you for helping.
I was thinking more along the lines of making the force field visible so the player *knows* there is a possible escape.