You should play Arabia because your assumptions are off. A small number of wonders and great people alone account for a fantastic number of historic events. You can get a religion much easier (less risk). Your UA generates early science and culture which makes the wonders less risky. Korea might have more raw science, but Arabia has better odds to build something like University of Sankore. The historic event income is great even without archeologists.
Is it that hard to protect trade routes? If one dies, just build another one? They are incredibly cheap. Its way easier to keep trade routes running than to keep golden age going.
If you want to talk about risk, how about the risk that Korea appears on a coast with very little land that just isn't viable for tradition? You aren't going to feed many specialists by working coast tiles. If you take progress or authority your unique ability is clearly, dramatically worse than Portugal's.
I maintain that the Seowon needs a buff.
and double science from citizen birth make it strong then? With a consistent boost to science going alongside a GA's boost to production and gold, you'd expect that alone to push Korea situation above a lot of other civs that people played with Tradition before, like Austria and Egypt. These civs were also struggling with this tree in the prior patch, so I considered this situation a Tradition issue, not a civ issue yet.
