The OP video.Which one?
The one about 11Q13
here should actually help a bit. That will give you some idea of who the Essenes were, and how they quite probably melted into Christianity, once their Messiah they had prophesied of who would arrive and die for the sins of the people around 32 AD, and rise from the dead came.
If you mean the videos at the top and the one I posted here YouTube Those were dealing with Tom Horn's idea about Wormwood and the Asteroid named Apophis and a near pass of earth on Friday April 13 of 2029. The Essenes come into that conversation due to their calendar system.
Extra Biblical sources are good sources for history that shows the Bible is accurate to the unbeliever. They also can help us understand Jewish idioms - such as the references Jesus makes to the Jewish wedding ceremony of Galilee in that time period.
To understand what Jesus said about "I go to prepare a place for you" it helps to know that was a thing the Jewish bridegroom said to his bride once she accepted his proposal. He would then leave and prepare that place for her and be gone for up to 2 years.
Only the Father knows is the response of the bridegroom to the good natured ribbing when friends or relatives would ask when is that wedding? Because in first century wedding customs the Father was the one who decided when.
Understanding the idiom isn't necessary to take the literal meaning, but it adds depth and certainty. We are then sure that Jesus is coming back for us, that He is preparing that wedding chamber for us and that when God the Father tells Him to get us, then He will go get us.
It gives us greater understanding. It doesn't replace what we learn in the Bible. Same with the Essenes and their history and writings. Or Josephus. They aren't held to the Biblical standard of accuracy but they add understanding that first century Jews took for granted.
My only concern is by what’s mentioned in a few points up thread, the Essenes have been wrong in some of their prophecy views, then they should not ever be mentioned when it comes to prophecy. They were not prophets.
Its interesting reading what you and others have written about them, but for me, I’m sticking with the Bible.