Outwardly liturgical tradition is, however, not considered sacred, save for the Eucharistic celebration. The oldest Divine Liturgy was practiced in Jerusalem under St. James. The East used St. Basil's Divine Liturgy thereafter. Last litrugical change (in the East) was made by St. John Chrysostomos (5th century). All three liturgies are celebrated to this day in the Orthodox Church, the last one being the "weekly" Divine Liturgy and the other two, under specific circumstances, as the liturgies of specific feasts.
So, while the content of the litugry is sacred and based on the Scripture (Gospels), the outwards expression of it, along with vestments and so on is not unchangeable.
But you points are well made regarding the meaning of the Apostolic Tradition and its validity equal to Scripture. In addition to the liturgical tradition and the Bible, the third elementnin the Holy Tradition of the Church are the Ecumenical Councils.
It is important to stress that the Chrch Tradition can never be contrary to the Scripture. But simply because somehting is not in the Scriputre does not of itself invalidate it as long as the Apostles talked about it or allowed it, as documented by extra-biblical sources.
True, liturgical tradition is not considered "Apostolic". But the "sense of the faithful" is often expressed in the Liturgy, even if unknowingly. For example, I believe it was St. Athanasius who argued vs. Arius that Jesus MUST be God BECAUSE even the Arians were worshiping Jesus as God during the Mass! Lex orendi, lex credendi, right? I would agree with you, that the various rituals are indeed subject to change, the language, and so forth. But the overall "scheme" of the Divine Liturgy is a teaching moment that extends back to the Apostles, I believe.
Brother in Christ