I see a color in your chart above that looks very close to snakebite. It may be exact, not sure, but IME it is important to get snakebite just right for use on NMM gold, among many other things.
You have a cold gray and a warm gray, which is cool. Very true that turqoise is needed. Lots of shades of brown is important. But ultimately, 3 things are needed to qualify as the best of the best for a line of paints. They are:
1) Good flesh colors. Stay away from making them overly pink (tho include one pinkish tone). A couple base tones to choose from would be nice, followed by a couple of shades that include a reddish tan, a greenish tan, and a golden tan. Then a yellow and a pink highlight. I would copy closely the old citadel Tallarn Flesh, Kislev Flesh, Bugman's Glow, Ratskin Flesh. Andrea and Scalecolour are good too.
2) Inks. Nothing crazy here just good strong primary colors. Intensity and saturation are what count.
3) Metallics. These, plus the mattness of their acrylic paints, is what made Scale75 the best in the biz. The key is to make super fine pigments that don't sink in suspension. Also, make a very dark steel, like Scalecolour's Black metal. I found their golds not quite as good, simply because I haven't messed around with them enough to find a clear way to do Bronze, Brass and copper. See also the old line of Citadel metallics.
Do those three and keep your costs where they are, roughly, and there is no reason that everyone wouldn't buy your paint ahead of anyone else. Oh, key colors to think of too would be something that equals VMC Dark Sea Blue which is also GW Incubi Darkness and P3 Coal Black. As I think of more I'll include them here.
I am going to buy that first set simply because you appear to have made a perfect Warlock Purple.
