It's actually all energy.
No, "it" is all a series of fields. Fields != energy. Mass may be
equivalent to energy as expressed in the equation E=MC^2, but
space is not energy, for example.
The only "Solid" stuff is just an energy field as well.
More specifically, the "solid" feel of matter is due to repulsion in electromagnetic fields, not actual contact with other matter.
The "Flux" theory is just a handle to explain how it may have come into being without an pre-intelligent source. Scientifically, nothing comes into being without an intelligent or engineered source, except in this one case of course. But it's all ancient history and subject to the whim and whimsy of the stroke of a pen.
Scientifically, nothing "comes into being"
ex nihilo, period. Matter and energy can neither be created nor destroyed (with the blurry exception of virtual particle pairs, but they re-annihilate almost instantly).
Even positing an "intelligent source," Creation
ex nihilo still requires the violation of the laws of thermodynamics. Not to mention the assumed idea that all things
must have been Created and thus need a Creator is an unfounded assumption to begin with, making such Creationist arguments worthless from the beginning.