Aight, I only hosted one and it wasn't optimal, but I think at this point I have a better grasp of how it's done properly.
Amount of listens varies to be honest, mostly go with your guts, listen to them until you think you know the songs well enough to rate them, but at the very least I think you should've listened to every song 3-4 times, more if needed, but I wouldn't go with less than 3 ever, even if I absolutely hate the song or if it's crazy impossible to understand.
And yeah, 4-5 days seems to be the optimal pace without rushing.