not familiar with Nikon stuff so cannot answer all you questions. The raw/nef file is just that, its not have any adjustments done to it. I am not aware of any software that will apply the settings in your jpg to the subsequent raw/nef file.
but if you look at you jpg setting in your camera, you maybe be able to work out how much sharpening, contrast and saturation was added. It will give you a starting point. The added benefit of using the raw file is that you can change many more things, like the white balance that may add some warms to the picture for example. Since you have the original jpg you should be able to compare the two easily enough. Also, if possible consider printing both, to check for differences.
Canon Powershot S95, Canon 6D,7D, Canon 40 2.8 STM, Tamron 24-70 2.8 VC, Canon 17-40 L, Canon 15-85, Canon 85 1.8, Sigma 30 1.4, 50mm 1.8, Canon 100 2.8L Macro, Canon 70-300L +Kenko 1.4 Pro 300DGX, Canon 430EX II and RS 4 Classic