Do you think it is evil to manipulate someone to get what you want?
It can be, and I'd say most manipulators are at the least, not good. But as with so many other things, it depends on the details.
The spectrum of manipulation ranges from things like causing another to sabotage relationships with kith and kin, to manipulating someone into attending the addiction counseling they need.
Manipulation by definition is a part of life and without it there would be chaos. People in the armed forces are manipulated so they become soldiers. Their minds are trained to follow orders otherwise they would just do their own thing.
For me its only "Evil" if you are doing it with the purpose to see that person become ill, hurt or dead. Sometimes a little manipulation can point a person in the right direction if they aren't too strong of mind.
Yes using someone or manipulating them is harsh and uncalled for. It is much easier to steer them in the right direction and allow them to make their own choice in life.