Dark Energy And Conservation Of Energy

If Dark Energy causing the expansion of universe
and unit volume of space-time must have a constant amount of zero point energy then how this is consistent with conservation of energy?

I read that one opinion is conservation of energy simply does not apply at cosmological scale.
(To me that seems quite unreasonable! So conservation is okay everywhere in smaller scales but somehow gets broken in bigger scales? Isn't that kind of like if you add up a really big number of zeros and you get a total different from zero?)

Another opinion seems that (if I understood correctly) gravitational energy is negative and as galaxies get farther away from each other
it gets more negative, so there is an energy loss, and that provides the energy needed for the expansion (and also photons in the universe lose energy as their wavelengths increase?).
(To me this logic seems like chicken-and-egg problem!)
(Also I would think that, compared to energy needed to create new space-time for expansion of the universe, energy coming from gravitational binding energy should be minuscule!)

My opinion is Dark Energy maybe a (very different) kind of particle that creates new space-time cells (each size of Planck length) when it decays. And if so that means total amount of Dark Energy in the universe must be higher in the past and lower in the future
(which maybe possible to prove/disprove with astronomical observations). (Isn't it also imply space-time maybe some kind of fluid/gas?)

Also if Dark Energy runs out someday, is that mean universe would end in a Big Crunch? How all space-time created previously would get destroyed back? For that to happen wouldn't Black Holes need the ability to pull back and destroy space-time?
(Isn't it also imply space-time maybe some kind of fluid/gas?)

Also if Dark Energy causing the expansion of universe why we still need inflation?
Isn't it possible Dark Energy was expanding universe since Big Bang by keep creating space-time?