Standard cosmological models successfully reproduce observed expansion histories but often leave unresolved why the universe exhibits a finite lifetime, bounded structural complexity, and discrete hierarchical organization. This paper introduces the concepts of CBASE (Critical Base State) and CREAL (Realized Complexity Index) within the framework of Existence-Quantized Geometric Theory (EQGT) as global structural bounds governing cosmological evolution. CBASE represents the theoretical upper limit of allowable structural complexity, while CREAL quantifies the complexity actually realized under background information pressure and observer constraints. By modeling the universe as a system evolving within finite complexity space, the analysis demonstrates that large-scale cosmic behavior naturally follows cyclic trajectories driven by structural saturation, resonant elimination, and information redistribution. Within this framework, the Big Bang and Big Rip are reinterpreted as phase-transition boundaries rather than fundamental singularities. The CBASE–CREAL formulation provides a unified structural connection between microphysical stability, atomic structure, and cosmological evolution, while preserving standard cosmological parameters as effective descriptions within observer-limited regimes.