PLease see my response to Athanasian Creed (odd name given his views) on your last point. Are you denying that Jesus Christ was God incarnate?
On the 1st century church point, I think you will find that it was quite different to 21st century evangelical services. For a start, you forget that Christianity did not arise in a vacuum but in a Jewish and Hellenistic religio-cultural milieu. Thus any 1st century church service would have had a distinctively Jewish flavour to it (and I'm not just talking about the Jerusalem church here): there would have been liturgy (indeed we know this from Scripture because of the various proto-liturgies produced in the NT) and quite a bit of formalism generally (except possibly in Corinth - but there St Paul seeks to correct the anarchy to which that church was tending). The ECFs such as Justin Martyr also give pretty good accounts of an average service in the mid to late 2nd century which is similarly liturgical and centred on the Eucharist. So, far more resemblance to particularly the EOC than modern evangelicalism.
A word about this dreaded concept of Tradition. "Tradition" began as exegetical - if excessively creative in some early writings. As for 'praying to Mary,' that became very excessive during the past few centuries, but every doctrine about Mary was intended to both set forth a point of Christology (for example, his being both fully divine and fully human) and to show Mary as a representative of the Church.
One of the largest problems with both confusion within and misconceptions about Roman Catholicism is that writings, preaching, practises, and devotions often go far beyond actual doctrine or dogma (not that everyone would agree with the doctrines themselves.) Simple example: besides other large problems Martin Luther addressed, some of which were remedied at Trent, the sort of 'penitential system' (pardons, indulgences purchased, etc.) which existed in Luther's day were highly distorted (if very lucrative. I find Martin to have been far more Catholic than some of those whom he confronted.) Just about everything (ordinations in monasteries to have priests to say Masses for the dead, for example) centred on purgatory and the church's jurisdiction - where, actually, about all there is to the doctrine of purgatory is a concession that we do not know what lies between the earthly life and the last judgement, and that there may be purification after we die. (What Dante Alighieri and Thomas More made of it is poetic but in no way doctrinal.)
I personally think that certain dogmas, such as the Immaculate Conception, would best have never been declared. But excesses in devotion , some of which were still prevalent in my youth (when it seemed all that RCs thought about was Mary and purgatory...), though they date back several centuries, indeed could make it seem that Mary is honoured more than her son. Devotional preaching, intended to touch the heart but not necessarily theologically sound at all (I'll be forgiven for saying Franciscans did it well) could make it seem that one could not pray to God (only 'through Mary,' when she was not too busy distributing the indulgences to those in purgatory which one gave to her when making the 'heroic act of charity'), or that Mary had some sort of parental authority which meant Jesus had to obey her even now.
Another sad fact is that Roman Catholics, including priests, used to think that humble obedience (I believe that because it is what the Church teaches... it is true because it is a church teaching) was all that mattered - and apologetics were unnecessary because no one who was a good RC would ever question anything.
I'm not suggesting that every Christian should agree with Rome (or indeed Constantinople) on all counts. Yet I would suggest that one be certain of what the actual doctrine or teaching is (it normally will be related to Christology, and in that be perfectly sound) before assuming it is at odds with Christian essentials (in which I would class Christology, the Trinity, and the early creeds.)
