My small fire steel and Vaseline impregnated cotton balls have traveled with me several times in my FAK. Mixed with my Band-Aids, alcohol swabs and other clutter I did not have any trouble.
Your spark right will probably look like a lighter on the screen and will probably get them looking at you closer.
For the rest of it study the list before you leave to fly every time as the TSA keeps changing the list as to what is acceptable and what is not.