I have no experience with flares or pyrotechnics so I thought it would be interesting to come at this from a very non-technical direction. I did read the report at the beginning of the thread and thought it was quite well done. However, I wonder if it might benefit us to start again with the 'see what is there, not what you expect to see' angle and do some more brainstorming on what the letters/words in yellow might read, as well as what these artifacts might be. Forgive me if it seems silly; can't hurt, though!
Could the fragment with letters be a portion of a sign/box taken from a ship/plane for use in holding over fire to cook critters? Would this metal withstand that degree of heat, and might this leave scorch marks?
The first things I thought of when reading the markings on that same bit of metal were along these lines:
HELP, SHELF, SHELL, HELD, RELEGATE, DELEGATE; LIGHT UP, NIGHT UP, HEIGHT UP, FLIGHT UP, RIGHT UP; *7.
Just my two cents!