I see it on the Flame board also, in my opinion it is a controversial subject that needs intelligent debate.

If I am allowed to inject my thought to the subject matter, then I would agree that Newtonian mechanics (or mathematics) actually explains, or rather, is similar to Einstein's theory of e=mc2

Newton said: f=ma

Mass is the common ingredient in both formulas.
If not acceleration, then what does the c2 represent?
How is force and energy related?

Perhaps the constant in the propagation of photon energy is not the speed but rather the accleration of the photon quanta/packets.

Can a force exist without the presence of energy? (potential or kinetic)

Einstein's formula of e=mc2 gives correct answers to experimental results.
The formula e=(u/k)c produces similar answers.