I don't understand any of this

[Ironside]

Oh well, as I have read it dark matter is the reason things can move out and then retract.

But let's face it, your guess is as good as mine. And if a fish farts in an aquarium, that is also something we both have to consider as a legit input to the discussion.

Not really. See they name the unknown based on what it's supposed to do. Dark matter is whatever that's the answer on why the galaxies doesn't win the star throw awards in the olympics. It would affect the retraction, but not the expansion directly.
Dark energy influences the expansion directly, but it's something entirely different. It's whatever causing increasing red shift aka accelerating expansion of the universe.
I think you've mixed them together. It's quite easy to do. The one coming up with dark energy were really not thinking about the risk of name mixup, only theme names.

Basically, it goes something like this. The formula used work fine on small scale and large scale, but are completly wrong on gigantic scale. So either the formula is incomplete or you fudge the numbers and acknowledge that you did that and tell everyone that you describe something real that haven't been discovered yet. Sometimes, the rest agrees with you on that. Sometimes, it's even correct.

Campare to "what caused the Big Bang?" There's certainly no seriously taken formulas to calculate that.

[Myth]

it might turn out that the whole idea of a big bang is making us biased and thus leading us into a dead end. We lack the tools and knowledge to look deep down enough, far back enough and so on.

[Papewaio]

it might turn out that the whole idea of a big bang is making us biased and thus leading us into a dead end. We lack the tools and knowledge to look deep down enough, far back enough and so on.

Other theories have been looked at ie static universe or infinite one.

Big Bang theory explains to a high degree the universe we are in and is the current best fit model. Once a better model comes along the physicists will be all over that just like Lenoardo Dicaprio does with his ones.