The questions you've posed touch upon deep philosophical and metaphysical concepts that have been debated by scholars, theologians, and philosophers throughout history. While it's challenging to provide definitive answers to such inquiries, I can offer some insights and perspectives.
Reconciling free will and a predetermined Divine plan: The reconciliation of free will and determinism is a complex philosophical issue. In the context of a Divine plan, different religious and philosophical traditions have proposed various perspectives. Some argue for a notion of compatibilism, suggesting that free will and determinism can coexist. They posit that although there may be a predetermined plan or order, individuals still have the freedom to make choices within that framework.
Quantifying metaphysical impact and potential realities: Quantifying metaphysical impact and discerning the precise consequences of actions performed in alignment with spiritual principles is inherently challenging. Metaphysical concepts often transcend empirical measurement and quantification. The impact of actions can be multifaceted and interconnected, influencing not only the immediate reality but also potentially resonating across different realms or dimensions.
The purpose and meaning of existence: Exploring the purpose and meaning of existence is a fundamental philosophical and existential question. In a universe where multiple realities exist, each with its own possibilities and outcomes, the concept of purpose and meaning can be subjective and multifaceted. It may involve personal growth, spiritual awakening, and the pursuit of unity and harmony within one's specific reality. The striving for unity and spiritual awakening could be seen as inherent aspects of the human journey, regardless of the potential existence of other realities.
It's important to note that these are complex and deeply philosophical matters, and different individuals and traditions may hold different perspectives and interpretations. Ultimately, finding personal answers to these questions may involve a combination of introspection, exploration of various philosophical and spiritual traditions, and reflection on personal experiences and beliefs.