Diet Tolkien is such a good term for it! I agree so very much! As much as I love your typical dwarf/elf/human type of fantasy land (Dragon Ageeee ), there’s just something about making it your own, creating your own species, and adding your own twists that just really brings a shine to your story.
And ooh, I do like that! I think that would be an interesting twist- working and fighting to NOT fulfill the prophecy and not be the Chosen One, doing what you want. Is it possible, or are you always going to end up a slave to Fate in the end? While I don’t think there’s TOO much wriggle room in the Prophecy/Chosen One trope, I do think that there is room enough to make it possible to grab somebody’s attention despite it all.
Limits to Magic systems and limits to the main character (also giving them flaws) is probably one of my biggest pet peeves when it comes to fantasies. I don’t need all of this OP nonsense. It’s probably why I enjoy the Dresden Files from Jim Butcher so much and others like it! I LIKE watching your average Joe or close to have to struggle, fight, and work for that win. Or even winning by just pure, dumb luck! lol