Add fire / lighting / special effects to video

Greetings! I have a stable video of musicians performing. The camera does not move, only the subjects. At one point in the video, I would like a heart prop behind the band to catch fire, and spread on to their clothing. At this point, the band takes their jackets off in the video, so the fire is stopped. I am open to using ideas of the animator- Creativity is a must! There is also some basic clean up, for example extending the background to get rid of the lights visible in the top of frame. There are a few instances where the subjects head goes in front of it, so that would have to be masked out frame by frame. There are 3 different videos, only about 3.5 minutes each of the same performance from different angles. I would need all 3 videos worked on with the same effects and output at high resolution with no quality loss. Please see the attached image. Thank you!