[Pwbeninate]

Here is an AE tutorial that may point you in the right direction:

https://www.creativecow.net/articles/dallos_matt/fire/index.html

[Pwbeninate]

In the inspector, you can modify the size of the layer.

[Pwbeninate]

It looks like they just threw a red layer on tip of the video and dropped it’s opacity way down. Pick the right blending mode (multiply?) and it should exaggerate the highlights making them glow.

[Pwbeninate]

Should be able to change the lenght in the Project Properties (Cmd + J)