Sola Scriptura does not claim to be the sole authority always and everywhere.
Scripture is the lone authority for faith and the Christian life, sufficient for understanding salvation. Nothing more.
Claiming sola scriptura means things is does not mean is factual error. Arguing against such a misrepresentation a straw man. Claiming other authorities exist is a red herring because sola scriptura does say anything about the existence of other authorities other than they cannot contradict scripture (something you have agree with). Calling sola scriptura a false doctrine is an appeal to ridicule. Arguing the Magisterium is authoritative for understanding scripture is equal to being authoritative over scripture is a false equivalence. Using scripture to prove any point begs the question in antithesis. Arguing against misunderstandings is moving the goalposts. Repetition is argumentum ad nauseam.
- Factual error
- Straw man
- Red herring
- Appeal to ridicule
- False equivalence
- begging the question
- Moving the goalpost
- Repetitive protest
There is simply no way any case made with so many fallacies can be reasonable and rational. Neither can it be scriptural, and I doubt it is what the RCC argues because if that is the way the Magisterium argues then it has proven itself NOT an authority.
What does scripture say?
Is that something scripture says?
What does scripture say?
Is that what scripture says?
Can you see the problem? If you use scripture to prove a point, then you have demonstrated scripture is authoritative to all that it speaks regarding faith and the Christian life. If scripture speaks to any point, you make then, again, scripture has been shown authoritative. Any point you make that contradicts scripture proves two things 1) the other would-be authority isn't authoritative because it contradicts scripture and 2) you've run into self-contradiction because you agreed no authority can contradict scripture.
I do not care who a protester is (or isn't), they MUST be able to form a better case than the one mustered in these two pages.
Now the facts of the Magisterium are that they do not hold themselves to be an authority above scripture. They do not, in fact, hold themselves to be authoritative over many things regarding faith and Christian life or their own existence. The Magesterium is established by the sacrament of Orders. It is more authoritative then the Magisterium

. There are three magisteriums, not one (ordinary, conciliar, pontifical). The Bishops of the Magisterium, are accompanied by trained theologians upon whom they rely. These theologians are Masters of Doctrine. The former holds the authority when it proposes a doctrine with which the Pope agrees, but they are dependent upon the theologians to make scripturally and (RC) doctrinally informed decisions, as well as Christ and the Holy Spirit and Christ's Successor (which is a post-scriptural second century term invented by Irenaeus and not found in scripture). According to the Roman Catholic Church, the Pope has no authority apart from the Bishops and the Bishops have no authority apart from the people from whom they were chosen, and they all represent Christ who provided the Holy Spirit upon whom they rely to understand scripture and determine sound and infallible doctrine.
And since the written word of God, the person of Christ, and revelation of God are all Divine (the logos, Person, and rhema) All those entities just listed receive their authority from a superior authority: God's word (whether logos, incarnate, or rhema). It is Catholic doctrine.
Does that mean an agency responsible for uniform instruction is not needed? No! The Magisterium is certainly something the Protestants are lacking but since the Magisterium can demonstrably be shown imperfect the Catholics have little basis for making Tradition and the Magisterium co-equals with scripture. The entire reason Protestantism exists is because of godless errors made in the RCC blatantly in contradiction to scripture. If the RCC leadership had listened to the Catholic men crying out for reform Protestantism might not exist. So you think about that because every single protest you will ever have against sola scripture always and everywhere come accompanied by the historical facts of the Reformation proving Catholic doctrine pertaining to faith and the Christian life (they were selling absolution!!!) imperfect and the RCC's own subsequent internal reformation. If they'd been perfect to begin with their own reformation wouldn't have been necessary, and if they'd listened to the Reformers (most of whom were good Catholics NOT wanting to leave the RC) you and I would not be having this discussion.