Noise Reduction: OFF
Firework photos are low-light photos, but the shutter speed isn’t usually long enough to incur a build-up of noise. Additionally, keeping it on will double your exposure time, which is unnecessary.
Flash: OFF
Shooting with a flash will only trick your camera into thinking it needs a short exposure time or brightening and enhancing smoke which would distract from the actual firework display. Keep your flash off.
White Balance: Daylight
Setting your White Balance to Daylight will give you consistent color across your entire set of images. Since you’re shooting in RAW, you can always tweak it later in post-processing and apply it to the entire set.
ISO: 100
Keep your ISO as low as possible for the cleanest noise-free shots every time.