Interesting, I've never thought about destiny that way. I don't quite understand what you mean though? If you're willing to share more, I'd love to hear it. 🙂
Certainly. I see the concept of destiny - in real life - as an eventuality that will come to pass according to (not in spite of!) one's choices and whatever other factors are at work. The future is just a place on the time stream that we can't remember and haven't experienced, like the final chapter of a book is for a character who appears in the first one.
When you transfer that idea to fiction, well, there you go. Some people look at a writer's machinations as the Hand of God - he or she controls everything that happens to the characters. I see the writer as destiny. The story will take on a life of its own, if it's any good, but the ultimate truth is whatever the author has chosen.
Thus, Buffy/Angel. If Joss intended them to fall in love, they were always going to fall in love. You could say he forced it, but the man is a storyteller; he's just doing his job.
Put another way, do the Bangels support James Marsters' statement primarily because it is pro-Bangel?
I didn't listen to it. Sorry. But no. There's no chance that "Buffy's feelings toward Angel are derived from her immaturity" or anything like that was ever in a script.