Yes, it's complex.

Your question about blowback is interesting. I've never heard of anyone having trouble with that when it comes to job magic -- though I have noticed writing opportunities coming my way when I did something to help a friend find job opportunities. You have to be very careful with love magic, of course, but then that blows up very easily: focus on helping the client become more lovable, which is the only effective love magic anyway, and the blowback won't hurt you...