The second part of your post you are making an conjecture. Here’s the thing, when Judas left the 12 and killed himself, they elected someone into his office. The office of the 12 is unique, as promised by Christ that they would rule and judge the new Jerusalem. They are not to be replaced by anyone, they will occupy this same office in the end of time.
[BIBLEDRB]Matthew 19:28[/BIBLEDRB]
So who will occupy Peter’s throne if every Bishop of Rome from the First Century to the end of time occupied the same throne? To assume someone inherits Peter’s throne means others would also have to inherit the thrones of the other Apostles. But we all know that is not the case. Again, there is no evidence that Peter every passed any office or authority to anyone. Everything is conjecture and speculation, nothing is conclusive.