In a word: yes!
Yes, you can use NDK with Kontakt from Komplete 7.
(Aside: when I got it, the kit had been saved from Kontakt 2 - the newer version of Kontakt will likely ask you to run a batch resave to update the files. It's not a problem and is worth doing.)
Tips: Back when disks were smaller, I gave NDK it's own partition; nowadays I probably wouldn't bother. But do put all your samples on their own physical disk, if you can - don't share the disk with programs, etc. That does make for smoother running.
NDK I only use with Kontakt, yes - it's the only way I think you'll get the best out of the kit without putting in a lot of work.