Filming these events would in no way be the cheap route. Telecine alone makes it a mismatch for most uses. Stick with your HD camcorder. Rove around so you have shots to edit with. Do grab a board feed if you can.
check you rimport settings. You may have ignored alpha (or forgot to change it back from invert alpha after importing some stills with alphas).
You said you downlaoded this file… sure it has an alpha channel at all?
Try a luma key.
Create the layers as needed in photoshop then just animate masks as desired. The sounf effect will bring it all together.
opening shot in my reel, if it helps: https://grinnerhester.com/reel.html
Make one more layer for the stencil and it can really take on a whole new vibe.
set the preroll to nada and set your settings to capture over breaks or capture on the fly after the tc break.
… better yet, shoot without breaking tc.