what happen if numenor didnt rebel against the valar?

[Zigûr]

Originally Posted by tom the eldest

sure the numenorean aretough,but mordor orcs,combined with the elite army of the easterling,the chariots of the balcoth,the horsemen of the variags,and the archer and mumakil of the haradrim is a devastating combo,even against the numenorean and the elves.

That's assuming a great deal about the quality of the Men under Sauron's control. We know that they "grew strong in those days and built many towns and walls of stone, and they were numerous and fierce in war and armed with iron" but that mostly proves that they achieved a level of military and technological competence which hardly seems "elite". Similarly the forces described here are characteristic of Rhûn and Harad in the Third Age. We know much less about what constituted their armies in the Second. As Belegorn has pointed out, even in their days of peace the Númenóreans had the capacity to be formidable in war. I would argue that their victory would not be assured, however, because Númenor was only militarily unstoppable (by Sauron) during the time of the shadow, not in the earlier years.
My point is, however, that in my opinion the most likely event in any "Faithful Númenor" scenario seems to be to be a war for the "soul" of Middle-earth, as it were, not unlike the War of the Last Alliance and the War of the Ring, perhaps, but on a vaster scale and potentially far more catastrophic. Given that Sauron's greatest problem at the end of the Second Age was that Gil-Galad had managed to rebuild his military strength during the years of Sauron's absence in Númenor, an earlier war against the Noldor which did not give them recovery time and against a not fully militarised Númenor might have simply resulted in an inconclusive struggle which wore down both sides.

Originally Posted by tom the eldest

I just read in the tolkien gateway that he and amandil were friends.trough amandil,ar-pharazon maybe originally friendly to elves,but he then follow his father footsteps and become on of the kings men

He was Amandil's friend, but there's no evidence that he was ever anything other than envious and hateful of the Elves, just like the rest of his faction in Númenórean society.
The example of Tar-Palantír shows that it was, for the majority, "too late" for redemption even before the reign of Pharazôn.