In opera and theater production, early-stage collaboration between creative and technical teams is often fragmented, relying on traditional meetings and remote discussions via video-conferencing platforms that lack spatial awareness, and visualization aids, often leading to miss-communication errors and interpretation biases. This paper presents our research on immersive virtual rehearsal platforms, aimed at bridging this gap. From February 13 to 19, 2025, we conducted a series of semi-structured interviews with different stakeholders in Performance and Art productions (directors, scenographers, stage designers, costume designers, and lighting designers) and examine their workflows, challenges, and needs. By mapping these insights, we identified key areas where immersive technologies could enhance collaboration, efficiency, and creative decision-making. Our thematic analysis surfaced six major themes, which we translated into design principles for a VR rehearsal platform prototype. Positioned as an intermediate stage between conceptualization and physical rehearsals, this tool enables key stakeholders to refine spatial planning, set design adaptability, and interdisciplinary communication in a collaborative virtual space. By integrating these findings, we propose a new digital framework that redefines the rehearsal process, merging artistic experimentation with logistical precision.