Perfectly stated.
:first:They seem to be in direct contrast.
eternal- no beginning
temporal- a beginning
We discussed this topic on the other thread. Do we need another time vs eternity thread?
Using your definitions, God is not eternal and temporal at the same time since God is uncreated without a beginning and end (eternal).
Being more theologically precise, God is eternal and temporal in the sense that He has no beginning/end, but still experiences endless duration vs timelessness. It is correct that His experience is DIVINE temporality, endless time AND eternal, no beginning, no end, from everlasting to everlasting (which does not mean eternal, so you beg the question by assuming your definition of eternal is the only possible one).