>through Peter God would tell us what is and is not a sin
God alone has the authority to define sin and He did so in His law. The pope of Rome has absolutely no authority to add to His law.
>It hurts me to hear protestants twist the plain meaning of the LORD
And it hurts me to know papists do not read the bible, they only believe the lies they've been told. It is obvious you have never actually read Matthew since you have not read just 2 chapters later when the promise given in 16 is fulfilled and the Lord gives the keys to all of the apostles together "Truly I say to you (plural), whatever you (plural) bind on earth shall have been bound in heaven; and whatever you (plural) loose on earth shall have been loosed in heaven."
>Insults and semantic arguments, claims that the LORD was babbling about rocks, I've heard them all and it's just painful.
The idea that the plain meaning of Matthew 16 has something to do with the management structure of a medieval corporation based in central Italy is incredible, and would have been quite a shock to the early Church, almost as incredible as making the claim while refusing even to pretend to defend it. This is not what a "plain meaning" is my friend, this is called a tradition of men, which one is utterly consumed in so that they take it for granted and reading the text of scripture so presume it they insert it wholesale into a text which knows nothing of it. You see the papacy here only because that is your tradition, but nobody without already being familiar with it has ever derived the papacy from this text, because it is not there.