Why is the First Light wavefrom and histogram showing up in my project footage?

Hmm because you set it up that way in First Light. Either turn it off in the first light or turn it off in the Cineform Active metadata status viewer. Tools is what you want to turn off.
Also RTFM

Fwiw,
I've actually had a few probs where after turnIng all tools off globally they still appear in random frames/ sections. Had to grab a few bits of source footage to put over the top to get out of jail.
It was random and very weird.
This may be what he's referring to...
As for a fix, reboot, reinstall Neo, pray.

Depending on what app you are using for your project (ie: After effects) it will show images that were cashed by the app. You will have to go File>urge All or something like that. May vary from app to app. Nothing to do with Cineform, rather a way video apps handle image cashing.