^ Impossible; since Galactic Guardians #4, tells us that the Absolutes were present trillions of years before the cosmos:
http://i.imgur.com/KIKbK5A.jpg
While Annihilation established that the Proemial gods where born after the cosmos came into being
No, i don't think they're Celestials, since there hasn't been any confirmed connection between them; but if we're gonna take guesses, id say that in light of recent events it's much more likely that they are, rather than at the time of 1994 (when the mini was published). Although i highly doubt that the writer meant for them to be the Celestials. They're just some Celestial-like group with no confirmed connection to the Celestials, much like the Makers from Micronauts.
As for who wins, i can't say for sure. Based on showings, Ubiquitor (who has no feats, but highly implied power) was overpowering Giraud (whose best feat is cauterizing Eternity who was infected with a disease, something which was felt across the universe, although from what i recall Giraud was portrayed as being inferior to Dormammu, merged with his 616 counterpart, who at the time period was at the peak of his power when he returned in an issue of Dr Strange v3), but like zop pointed out, Giraud was exhausted; in fact, he specifically said that he was significantly depleted. Based on feats, White Phoenix most likely takes it.
