I analyzed/established the pitch/key for every single percussion sound. But, I did not pitched them to reach a certain note - not even one single sound got tuned like that, they are in the original keys they were played in - there is absolutely no pitching involved from my part, not even a few cents.

Of course, you can do that. To exemplify, if you have a kick who is in the right key, but fits even better into the song when you change the pitch up or down a few cents, you should definitely do the change. Just beware that pitch is a destructive effect and can make your samples sound odd. Anyway, as a producer you should already know that you must always use your ears.