Gradine
The Elephant in the Room (she/her)
I wouldn't even call 1453 dark age any more but early renaissance.
Oh the Dark Ages, probably the most egregious Eurocentrism in world history. Which is a pretty damn high bar, all things considered.
As to the dilemma of the OP, I think the bar is comparatively low when it comes to exploring and playing with historical tropes in a simple home game. My personal belief is that the only two things you really ought to try to do to clear that bar is:
1) Try to be as respectful as possible of the source (both the historical cultures and the modern descendants of said cultures)
2) At the very least, do no harm (as in, do not promote false stereotypes used to justify actual historical atrocities and/or modern-day bigotry)
Again, if we're talking just a home game you've got a lot of leeway there and it ought to be a pretty low bar to clear. It's just that, like [MENTION=6683613]TheCosmicKid[/MENTION], I'm skeptical of both the OP's ability or even desire to clear those bars.
That said, the proposed "role reversal" is not a reversal of "roles" at all. What's being described is exactly what happened historically, you've simply swapped the continents. You've only moved the Christian European imperialists to the Americas and vice versa. Now, you could actually do some interesting things with a premise such as that; a "here is what it's like to be subject to a imperialist subjugative force" type of campaign. But that's a much harder line to tightrope, and would require a lot of nuance and care to pull off. And there are much easier ways to tell that type of story without flipping the historical tables and villainizing cultures that suffered genocide at the hands of the exact same forces.
Again though, it's your home game, low low bar, do what you want. But I'm not seeing many positives to come from pursuing this type of campaign in this type of style.