EOSC-ENTRUST aims to establish a European network of Trusted Research Environments (TREs) for sensitive data by developing a common blueprint (ENTRUST Blueprint) to enable federated data access and analysis. The project is supported by four Driver projects representing key use cases in human genomics, social science data sharing, clinical trials data reuse, and public-private interactions in health and environmental data. These Drivers help validate the blueprint, provide user input, and identify gaps in existing TRE services. The deliverable report refines the requirements of these Drivers, outlines their use cases, maps a generic user journey, and conducts a gap analysis to inform the next version of the Blueprint. By aligning user needs with the development of TREs, the project contributes to enhanced European interoperability and provides a framework for designing TREs that meet research and data-sharing demands.