Black powder, or a black powder substitute such as Pyrodex. Smokeless powder (modern gun powder) should not be used in a traditional muzzle loading firearm.

Yes. It is a valid substitute for black powder.

Pyrodex , clean-shot , Or tripple 7

Most recommend is 3F powder, either true black powder or the "synthetic" or black powder substitute equivalent and between 25 and 30 grains should due nicely.

Larger grain black powder, such a fG or ffG. Black powder substitutes, such as Pyrodex are not intended for use in propelling fireworks. Pyrodex R could be tried- rmember it is measured not by weight, but by volume.