This is both false and simplistic.Just stop before you completely embarrass yourself. There is no confusing of parables. Jesus says the key is to use the same symbols in order to understand all parables (spiritual concepts).
An example of your error would be how the word "leaven" is used. Sometimes it is in regard to wrongful teaching as in beware the leaven of the Pharisees. But it is also used to describe the rise of the kingdom life. So one is bad and the other is good.
So which is it?
It is both.
But because you only see in one dimension you will miss every teaching in the bible.
Are you able to do that with YOUR key?
Could we use YOUR key to explain every other parable?
Yes....all the parables can be understood through the key parable...the Sower. Jesus is the Sower.... and he is describing who WE are. And this is from an eternal perspective...something you mock.
The bible is written from an eternal perspective.
So with an understanding of the 4 destinies presented to us, we can look at all other teachings through it.