Hi Harry, welcome to PF!
The best way to learn about a topic is to do some basic reading on it, and then try to ask more specific questions. Try starting withhttp://en.wikipedia.org/wiki/Dark_energy" .
There are lots of reasons why what you're proposing doesn't quite fit; that article should point to some of them. If there are any specific questions you have, ask away!This is an incredibly confusing and inaccurate response.
Dynamic: It is ambiguous what you mean by 'dynamical', but in many respects dark energy is one of the least 'dynamic' things in the universe.
Inhibits space: what is that supposed to mean?
slowing down due to its repulsive effect (cosmological constant): The 'repulsion' is what leads to accelerated expansion, not slowing down. The expansion of the universe is accelerating. And the 'cosmological constant' is another way of describing 'dark energy', they aren't altogether separate concepts.
Einstein: Einstein did not 'debunk' the cosmological constant. The famous quote and story is in regards to his methodology and the reasoning behind his actions, not the constant itself---which we believe to be effectively correct.