Those are some great guides! Always love to see more videos of how people play on P99.
I have an alternative method for the Grave Master if you want to give it a go.
https://www.youtube.com/watch?v=qS3uoIHTu_c . The idea is you can kill the pather in the hallway between the graveyard and entrance to the royals area. This is because he spawns there, and he will be close enough to his spawn point to not gate at low HP. Then you only need to worry about the Grave Master and the one add. I just /q before the pather dies to avoid faction hits.