The Supersymmetric SO(10) GUT based on the $210⊕ 10⊕ 120⊕ 126⊕ \bar 126$ Higgs system and only spontaneous CP violation has 24 real superpotential parameters. It is compatible with all current low energy data and yet has enough freedom to accommodate the still unknown Leptonic CP violation and neutrino mass scale parameters. It is thus the New Minimal Supersymmetric Grand Unified Theory(NMSGUT). We compute the superheavy mass spectrum, couplings and associated gauge evolution threshold effects and determine the regions of the parameter space compatible with perturbative unification, baryon stability and Weinberg angle while permitting spontaneous CKM CP violation. We show that the structural requirements of spontaneous CP violation always tend to raise the unification scale $M_X$ and with it the mass of all superheavy multiplets and thus to suppress Baryon decay. These scales can be raised even close to the Planck scale so that the NMSGUT gauge Landau pole becomes innocuous. This scenario lends support to our earlier speculations regarding GUT dynamical symmetry breaking and induced gravity via UV condensation at this Landau pole. Fermion mass formulae and the effective superpotential for Baryon violating $d=5$ processes - which contains novel channels due to the $120$ Higgs - are derived to prepare for the next round of detailed analysis of the phenomenology of this model.