The limit is that whatever doctrine the Church might refine today cannot contradict any previous divinely revealed doctrine, and so any apparent innovation cannot condtradict either the scripture or other de-fide statements of the Church.
Both penance and purgatorial cleansing is in the scripture, as I showed you. It is your personal, fallible interpretation of the scripture that is in contradiction. Bu tthe real test is not even if they are spelled out in the scripture, but that they do not contradict it. For example, several marian dogmas are indeed merely alluded to by the scripture. They do not, however, contradict it.
Some parts of Mariology don’t bother me. If someone wants to claim she was taken up into heaven, have at it - scripture doesn’t say, and I was not there.
What makes my skin crawl - if not my tongue to rot - is stuff like this:
“48. Let all, therefore, try to approach with greater trust the throne of grace and mercy of our Queen and Mother, and beg for strength in adversity, light in darkness, consolation in sorrow; above all let them strive to free themselves from the slavery of sin and offer an unceasing homage, filled with filial loyalty, to their Queenly Mother. Let her churches be thronged by the faithful, her feast-days honored; may the beads of the Rosary be in the hands of all; may Christians gather, in small numbers and large, to sing her praises in churches, in homes, in hospitals, in prisons. May Mary’s name be held in highest reverence, a name sweeter than honey and more precious than jewels; may none utter blasphemous words, the sign of a defiled soul, against that name graced with such dignity and revered for its motherly goodness; let no one be so bold as to speak a syllable which lacks the respect due to her name.
49. All, according to their state, should strive to bring alive the wondrous virtues of our heavenly Queen and most loving Mother through constant effort of mind and manner. Thus will it come about that all Christians, in honoring and imitating their sublime Queen and Mother, will realize they are truly brothers, and with all envy and avarice thrust aside, will promote love among classes, respect the rights of the weak, cherish peace. No one should think himself a son of Mary, worthy of being received under her powerful protection, unless, like her, he is just, gentle and pure, and shows a sincere desire for true brotherhood, not harming or injuring but rather helping and comforting others.”
http://www.ewtn.com/library/ENCYC/P12CAELI.HTM
If that doesn’t cross the line into worship for you, it does for me. Better for my tongue to rot than to give the honor due God to a creature.