Texture On Plane Issue? I'm using a video as texture on a plane.  It's a 10 sec looping video, but is a fireplace and appears seamless.  The issue is, my project is nearly five minutes long, and I only need the video in three locations, lasting 70 sec, 1 sec and 35 sec, respectively.

I'm confused as to how to do this most efficiently, without having to run the video in the background for the entire project??
The video texture doesn't need to continuously run in the background, as blender draws or renders a frame where the texture is visible it will read the one relevant frame from the video that it needs, this is similar to it reading any other image textures in your scene. As you are using a small video it will most likely be cached in RAM while it is being used and have little impact on performance.

To prevent your fire from always being visible you can animate the visibility of your plane both in the viewport and the render.