I've started playing on the Korean servers, and I am planning to try running some of the content with my friends here. Would there be any complications in posting videos done on the Korean servers?

Some things I can think of are: Timers are in Korean, but the time at least is visible in the format everyone is used to. (mm:ss) The game version is different; which means Korean servers are at a previous update. I believe it's at 6.1 at the moment. Runner's ign would be in Korean characters.

This is all I can think of at the moment, but if it would be just fine to post the runs, I guess that works too :D

Only thing I can think of off-hand is I don't know how the regionalized version updates coincide with things like hotfixes, addition of Trusts to various dungeons, etc. So when they change how a dungeon functions and it gets updated here to reflect that, those runs might be effectively inaccessible to you until the Korean version gets updated as well.

That is something I didn't think about. Yeah, as the Korean servers get updates 6 months to a year late compared to the global servers, Korean servers would access those contents way later. As for the hotfixes, I think the Korean servers apply them as soon as they can (or sometimes include them in the content updates) so that the game doesn't have to update that often. For instance, the fixes on experience from early Endwalker were included in the 6.0 update here.

I'm actually wondering if Korean servers would need a separate category or even a separate game category. It's the same game, but there are minor differences here and there.