5. Unfortunately ( or fortunately ) this is one of the key moments in fantasy RPG games/movies/books. Frodo is the chosen one who can resist the power of the ring and is trusted to take it to Mordor. The Dragonborn is a born man who can absorb the souls of dragons and use the Tu'um, which means he is the one destined to save us from a great and terrible evil. And so on and so forth. It doesn't make the game any worse or uninteresting, but I understand that no one wants to see Mary Sue for the hundredth time in a row. I agree.
You cannot avoid this really. If something world altering is happening you want to follow the one that is going to resolve it. Otherwise what's the point of the world altering event happening, if your following a random farmer that isn't involved into it at all. Even if the event is much smaller in scale like a conflict in a city or something you still want to follow the major players in that conflict, not the random guy involved into it. Like I highly doubt anyone was thinking while watching Game of Thrones it would be more interesting if instead of following the Kings, The leaders, The legend swordsman, it should have followed a random soldier involved in the war. It might have been interesting for one episode or something, but for the whole series? Fuck no.
It's the same in everything that's non historic really. The main conflict or love interest or whatever in the story always revolves around the main character. That's why he is the main character. If your watching a movie about a bank robbery do you want to follow the detective that catches the robbers, or the agent that is closing off the road?
And it makes sense if you think about it. A story needs to have a proper ending and that means the main event happening needs to end. If your following a random guy involved in the event instead of the main resolver, the ending will in most cases be shit since it gets solved with minimal involvement of the main character. Like the ending of the War of the Worlds
Historic is the only exception on this rule really since you already know how the main event ends. Following Hitler in a WW2 movie isn't more interesting than a random soldier, since you know before the movie starts the ending of the war. Following a random soldier might even be more interesting as you don't know his ending.
Anyway that's enough rambling about The chosen one and all that. I agree with Woody that you should just lean into the tropes more then trying to reinvent the wheel. They are common tropes/cliches for a reason; they are popular. And besides there aren't that many Adult Fantasy games out there compared to the modern settings ones, so anything you make is properly a bit of fresh air compared to the dozen modern copies thrown out every day.
Only things I really would advice is to always keep the main story clear and not get lost in (meaningless) countless sex scenes. Otherwise it can easily come across that your milking your game instead of actually continuing the story. It's the same problem a lot of modern setting games have, but it will feel more exaggerated if you got a major event happening that is promptly ignored for several updates for meaningless side stories and sex scenes.
The other one is the combat mechanics in your game. I cannot think of one game where I liked the combat mechanics. They always just suck horrible. Creating a good combat mechanic takes an absolutely shit time of work and skill. If your a new Dev (and it seems you are) I would highly advice to not have any combat in your game.