"While I can see why you interpret these verses the way you do, I see it a little different. (Shock! :) I don't see the angel and the elders as actually having offered the prayers, but only the incense. The incense represents the prayers, but are not the prayers themselves. The parallel is to a regular Temple service, wherein the priest would offer incense while the people prayed (directly) to God."
Actually, incense is seen as a sublime offering to God and in a sense is a prayer. Your comment reminds me of a verse/refrain we will chant tonight at the Presanctified Liturgy:
"Let my prayer arise as incense before You and the lifting up of my hands as an evening sacrifice."
(I have a concordance and I'm not afraid to use it ....)