Because you can’t record over an hour on PlayStation so I want to know if I can live stream it.

Yes absolutely!

I don't know how YouTube exactly works, but make sure that your video is in a video that's permanent on your YouTube account .

On Twitch, if you have turned on to store past broadcasts, they get deleted after 14 days. But if you highlight something, it'll never get deleted.

Youtube streams can be saved after streaming and viewed like regular Youtube videos, so it would be all fine.