Can the magisterium issue NEW teachings of the Faith?
Can the magisterium change articles of Faith?
Can the magisterium get rid of articles of Faith?
The answer to this is 'no' because EVERY article of Faith that we are required to hold now, is the same that was required of the Apostles and of 1st century christians, either explicitly or implicitly. Therefore, when you argue that the magisterium is 'always reliably safe' or something along those lines, you are indirectly giving them freedom to add/subtract from the Faith, which freedom they do not have - because the FAITH CANNOT CHANGE. The Faith came before the Church, since the Faith existed (imperfectly) in the Old Testament. As Christ said "I came not to destroy but to fulfill."
As Christ warned us 'beware of wolves in sheep's clothing." Who would He be warning us about, except the hierarchy? Why did St Paul need to rebuke St Peter, if the magisterium is always 'safe'?
When one says that 'dogma is the rule of faith', the way I understand it is that dogma refers to 1) articles of faith and 2) infallible declarations by previous magisteriums. Therefore, dogma covers all REQUIRED beliefs.
If the current pope/magisterium fallibly contradicts an article of faith or previous infallible statement (yes, it can happen), then they are anathema, as St Paul told us. There's no other way to understand it and this view is completely Catholic.