Can you record on Nintendo Switch, e.g. Get a copyright strike from smash bros on youtube because of the music?
Yes, Nintendo is tough there.
So rather make it out and store your own?
It always depends. They have no claims so if you have under 50k views nothing will happen. There's no bot running over it
I always turn off the music in all games and don't add any copyright music then you're on the safe side.
You don't get a Nen Strike. Your video will either be claimed and monetized by the author (so you can't earn any money with it yourself) or, in the worst case, be taken down by YouTube