Fate or free will is actually a silly question. Free from what or from whom? What are you seeking to be freed from? The question is often of more substance than the perceived answer. It's about the Battle of Wills; the essence of every spiritual and psychological pursuit. 

This is a bit of a paradox but so is everything of real value. 

What is fate? We are all born into something when we start our lives, we are born with a specific physical appearance, into a specific family, with specific traits, and have had specific & unique experiences, etc. This is fate, destiny, the luck of the draw, whatever label you choose for it. It would be foolish to ignore this. Most people don't actually deny this exists, that fate exists in this understanding, they'll just argue against it to direct their will somewhere else. 

Understanding that some of the hardest parts of your life can be seen in your chart, "fated," is actually quite liberating. You can find grace for yourself knowing that you didn't do anything wrong and that those moments will lead you to your greatest evolutionary steps. Other moments or encounters that seem fated can be immensely powerful and joyful - the blissful feeling of living in alignment.

Quantum physics is based on the idea that everything is predetermined, other than random quantum jumps that can't be influenced by us or otherwise, by definition, they wouldn't be random. But this theory only proves the interconnectedness of all things. And, perhaps more importantly, who is doing the determining?

What is free will? If you know yourself well enough, then you can catch yourself in the present moment and in the present moment you will always present yourself with new options and new possibilities. This space can be understood as "free will." This is where you consciously choose how you react to the world. Free will is how you respond to your karma (karma as in cause & effect, not a form of punishment). Free will is the space between life happening and your response.