I am an experienced Unity GearVR developer, having authored or collaborated with several applications for 360º vídeo visualization and VR games. I have been working with clients all around the world for years, I'm used to self-manage and to articulate with different time-zones.
As for the project, I am familiar with 360 video interaction on Unity and with the required UI mechanichs to enable the functionality you require.
I do have a question regarding the flowchart: is the application supposed to have a Unity+Unreal version? Or do you intend on choosing one engine of the two?
Thank you for your time.