Entropic Suction Theory v2 (EST v2) is a unified theoretical framework deriving gravity, cosmological redshift, Newton’s gravitational constant, F=ma, and the equivalence principle from four axioms about energy, motion, work, and entropy. The central result is that gravity scales with total nucleon count, verified across nine solar system bodies to within 1.5%. Newton’s gravitational constant G is derived to 0.11% agreement with the measured value. The Hubble constant H₀ is identified as the natural resonant frequency of the substrate medium, derived from the per-dimension bleed rate of hydrogen’s zero-point motion. Cosmological redshift is shown to be intrinsic photon energy loss rather than metric expansion, reproducing the linear Hubble law without dark energy. F=ma and the equivalence principle are derived from nucleon coupling to the substrate, closed through Axiom 1: matter is energy, therefore inertial resistance equals rest energy divided by c². Original predictions include proton weakening over cosmic time rather than disappearance, a three-photon confinement endpoint, age-dependent stellar surface gravity, and radioactive decay as deterministic threshold failure rather than quantum probability. This submission includes the main reference document (Version 21), three technical supplements, and an origins paper documenting the discovery sequence from first principles.