Shouldn’t I put Itunes in the New DJ Partition I’ve created on my Laptop
How else will I update tracks on this partition?
Is there anything else that I should add to the partition other that my dj software (Traktor), and Itunes?
I take it you mean the music folders only right and not the applications themselves (theres no real point in putting the apps on there as well cluttering things up).
Well, won’t i need the apps on the partition as well? Shouldn’t I be able to boot to only this partition?
Sorry didn’t realize it was an entire partition for the OS as well, my bad - carry on 
If you’re booting into that partition just for DJing and iTunes is one of the programs you use to organize tracks then yeah throw it on.