composite 3d objects into a 2D video which is took with fixed camera

What I am trying to do

I am trying to composite 3d objects into a 2D video which is took with fixed camera.

I want to use Sequencer to control and edit the actor’s movements while watching the original video being played back.

I learned how to use Composure Compositing window and compositing as a preview while dividing into layers from this Real-Time Compositing with Composure ,but I did not understand how to edit while moving the time axis of the media texture as I described above.

Questions

  1. Is it possible to create a thin overlay so that the media player image is visible from camera’s perspective in Sequencer?
  2. How can I make Media Texture also play along with the Sequencer time axis?
  3. According to my research, blender has more tutorials on what I want to do, compositing on a 2d fixed video. Why is that? Should I use blender instead of unreal engine? I’m asking this because I think compositing on a 2d fixed video is a basic thing on 3d vfx but there’s no tutorials/learning assets on this.

(Please tell me an solution if you can answer this additional question as well.)

Thank you.

Did you manage to solve this?