It's common misconception that you NEED it. Of course you don't need c/f, that's like saying you NEED to use the Mystery Method or you NEED to be this personality type. There are many ways to do this and you just need to do what works with you rather than trying to intimate someone else. It works for me because it comes naturally now and I love it. I find that when I drop it that things can start less than smoothly. It probably attracts a certain type of girl too.
Think of all the badboy types, are they c/f? What about guys that are smooth? Artistic types that girls like? Manly men? And look at all the schools of pickup there are. There is one single way to do this, you just have do what fits yourself. Some people like Mystery because it's scientific and they like having canned material, some people like Juggler because it's natural and lets you make connections with people, some people like Ross Jeffries because they.. um.. are creepy? I like to take what I like from everyone and make my own conclusions and I would advise everyone to do the same rather than following one guru mindlessly.
PUA and DJ is just semantics, they have different meaning to different people. In general PUA refers to someone who picks up girls or learns to for a living/hobby. A DJ is usually considered someone who is a real man, a successful person who is also a great guy with ethics and also gets a lot of girls. The main difference is that a DJ doesn't usually go after girls and they aren't the most important thing in his life because he has his passions but a PUA is always trying to get girls. Someone told me "The main difference between my PUA friends and the DJs at sosuave that if a girl flakes on the DJ he won’t bother with her or next her unless she makes an effort for him while a PUA will try and work out a bunch of different ways to get her". Make your own conclusions.