I did something similar, except using Blender, but same concept should still apply… basically all meshes were set to have their origin to 3D cursor (it was positioned at 0,0,0) so when they were imported into UE4, all of them can be selected and just dragged into the viewport, keeping the correct position as they were in blender because of the pivot being at 0,0,0 but mesh whatever the location was. One thing to keep in mind is to apply all transforms first, and then set the origin to cursor. As for cameras, I first used a separate mesh that had bones and in UE4 I could just attach the camera to them and set it to be hidden in-game, but due to later changes regarding the field of view, focal length, etc. I ditched that and placed cameras manually in UE4, kind of eyeballed it, but it worked out well.