A somewhat-old man once bothered me SO freaking much (I encountered him regularly), so I literally only imagined him with grey energy warping him and affirmed as the following; "(his first name only) is dying", I did that for about 15 mins and literally few days later he was taken with an ambulance to the emergency room. He's been in a bad situation ever since.
I didn't use any runes or any other thing, just this small affirmation with grey energy, plus the anger and hatred I had for him, and he almost died.
TL;DR Yes, I guess you can curse without using the full name, in case you know how they look.
Be careful though, you need to clean your aura and you need to make sure your aura is stronger than the person you want to curse.
As for white magick, I also didn't use a full name to help someone I know.
Hail Satan!!!!