Is everything predetermined?

This is kind of a tricky question. In the first place, it's one of those that I've written about earlier that is really a statement disguised as a question. When a person wonders about fate, determinism, free choice, free will, etc. s/he is usually basing the question on the assumption that this life is real. So the strict answer, from a non-dualistic perspective, is that nothing here is predetermined because there is nothing here!

Are we destined to return to Truth? Yes, but only because that's all there is. Nothing exists other than Truth, God, the Eternal, whatever label you wish to apply.

Within this earthly illusion, though, are things already determined? Kind of. Our mind, which exists outside time and space, chooses which illusions to view. So, in that sense, there's choice. Once we believe we're here, there are obviously choices to make -- choices that seem meaningful at the time, but later are revealed to be meaningless.

It's kind of like getting on a ride at an amusement park. You choose to get on the ride. Once you're riding, you can make a series of 'choices' like which way to lean, whether to put your hands in the air or hold on, or whether to close your eyes or leave them open, etc. But ultimately, the only choice that matters is that you chose to get on the ride. All the other things might affect your perception of the experience, but whatever you do ON the ride, the fact remains that you're taking the ride.

Like all metaphors, the amusement park example can only be taken so far. But, you hopefully see what I'm getting at. Choice, like anything else here, is a relative truth. It depends upon what you are comparing it with.