Consider an organization planning to configure M365 application access, implement access for external users, and deploy Office 365 workloads and applications. What factors should the organization prioritize to ensure seamless integration, robust security, and optimal user accessibility across these tasks?

1. When configuring M365 application access, what steps should be taken to align user permissions with organizational policies while maintaining flexibility for various user roles?
2. For implementing access for external users, what measures can be employed to balance security concerns with the need for collaboration? Share any potential pitfalls and how they can be mitigated.
3. In planning for Office 365 workload and application deployment, what strategies can ensure a smooth transition, minimize downtime, and enhance user adoption? Consider factors such as user training, support structures, and phased rollout plans.

Draw from real-world scenarios, case studies, or hypothetical situations to illustrate your points. Discuss any trade-offs, challenges, or innovative solutions that might arise during these processes.