They would get applied last. So if you individually Color Correct a layer, that would happen first and the noise effect you applied to adjustment layer would happen after.
For noise reduction or sharpening, it’s probably better to apply that to the individual shots. If you have 5 shots with 5 different levels of noise reduction needed(or maybe on 1 shot not needed at all), you would end up having to create a bunch of hold keyframes for each cut. Better to tailor those effects to the individual shots.
Johnny Cuevas, Editor
Thinkck.com
“I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work.”
—THOMAS EDISON on inventing the light bulb.