I'm a believer, conditionally.
Fate is when you hold the girl of your dreams in your arms and think how all this was meant to be, but she is thinking with her Free Will in the back of her mind: "OMG, how do I get rid of this creep?"
The Universe could be deterministic or it could all be pure chance - both seem paradoxical to me. The only constant I can think of is change, which gives rise to every possibility coming into being.
Karma is when you stub your toe against a nightstand in the dark and yell "GODFUCKINGDAMMIT!!!" Hissing against the pain, you realize you should have turned the light on (and maybe the tree that went into making the nightstand really did not want to be cut down). Echoing in the darkness of times past is some Zen sage saying, "Whenever you suffer evil, then remember all the evil you have done over an infinity of incarnations." Basically, don't complain. After a billion cycles of existence, muddy water clears up on its own. Or it doesn't.
Sneaking in the vicinity of Karma is that less comfortable concept of Sin, which is a smug serial killer sitting in a courtroom who committed such horrible acts that even atheists hope there is a hell, cause hanging is too good for him. What makes it worse (and unfair!) is this murdering asshole has hot ass groupies outside holding signs saying he is innocent and they want to marry him. There is also a sad forensic psychiatrist giving an interview saying the accused had a bad childhood and needs special care. Resentment, guilt, shame and revenge all tangled up into a moral order that keeps generating more Karma.
Astrology for me is best typified by the old saying "The stars influence, but do not compel." So everything in the Universe is in this interdependent tension and I have a little toolbox of symbols by which to perhaps calculate what could be mirrors of my soul. I still can't answer how twins born at the same time with the same horoscope can go on two different path - one a king, one a beggar. Maybe a minute's separation makes a difference. I can try do magic by drawing on these influences, maybe changing my "fate" or making my karma better or worse, but at least I am having some fun fumbling in the dark with guarded toes.