I'm gonna answer the arguments in order he posted without quoting them. Lol
1. As long as there is 1 legitimate bishop the church has not fallen. See arian crisis
2. The reason the church and all of the west has fallen and billions must die is because we are in the end times, and revelation said this would happen
3. St Robert Bellermine (Church Doctor) said a heretic is defacto not the pope anymore, kinda obvious
4. No precedent means nothing. That is not even an argument
5. That how do we get a new pope argument is literally Jay Dyers. There are still preists and bishops with apostolic succession anyways.
6. Your faith is useless and you are not a Christian. Pleassse read the Bible