You asked about the role—or perhaps better the “position”—of Christ in Christian prayer.
It is common among the Fathers of the Christian East, and thus among many Orthodox authorities, to say that one should pray “in” the Holy Spirit, “through” Jesus Christ, and “to” God the Father, though it is important to admit at once that, like Catholics and Protestants, the Orthodox do not always practice what they preach in this regard and often formulate prayers which are directed to the Son. One thinks above all of the “Jesus Prayer”. You will recall in this regard the point I made in my paper, “Disagreeing to Agree”, about the formulations “our God”/”God” in relation to Christ (see p. 11 of that article here).
As for traditional sources, the key Biblical text would almost certainly be Ephesians 2:18: “Through Him [Jesus] we have access in one Spirit to the Father”, though one could also mention Romans 1:8: “I thank my God through Jesus Christ”. Among the Church Fathers, Origen is quite insistent in drawing out the implications: “If we understand what prayer is, we ought not to pray to anyone born [of woman], not even to Christ Himself, but only to the God and Father of all, to whom also our Savior prayed…. For when he heard, ‘Teach us to pray’, he did not ‘teach’ them ‘to pray’ to Himself, but to the Father, saying, ‘Our Father, who art in heaven’, and so forth” (On Prayer, 15.1). I might add that when Origen uses the word “all” in the phrase “the God and Father of all”, he doubtless has in mind the expression “the God and Father of our Lord Jesus Christ”, which recurs in Romans 15:6, 2 Corinthians 11:31, and Ephesians 1:3.
Again, though, it is important to underscore the fact that there is nothing systematic about such a practice in Christianity; indeed Origen himself ignores his own rule on a few occasions. There is nothing surprising about this, of course, given the “spiritual economy” of Christianity and its stress upon the Divine “presence”, and you will certainly wish to word the relevant section of your paper in such a way as to acknowledge the many Christian exceptions to the rule of “through” Christ “to” the Father.