Nice work! Personally I prefer the look without your extra curves adjustments, a little more subtle. I’m working on a new grade for my edit as well, inspired by your efforts here. I’ll try out your LUT too, thanks for sharing!
I agree that the original brightness is quite adequate in most places, and no global LUT is going to fix it. The extra contrast in the last screenshots was just to see how bad the brightest shots fared.
I’m inclined not to add grain but I could see how it looks overlaid with your LUT.
The comparisons above with the LUT + Curves + Grain have ruined me on the ungrained version - now the skin tones look way too plastic-y without it, at least to me.