[Raynor]

What was Saurons' actaul plan with creating the Rings?

He made the one ring to rule over the elves:

Originally Posted by Of the rings of power and the third age, Silmarillion

but secretly Sauron made One Ring to rule all the others, and their power was bound up with it, to be subject wholly to it and to last only so long as it too should last. And much of the strength and will of Sauron passed into that One Ring; for the power of the Elven-rings was very great, and that which should govern them must be a thing of surpassing potency; and Sauron forged it in the Mountain of Fire in the Land of Shadow. And while he wore the One Ring he could perceive all the things that were done by means of the lesser rings, and he could see and govern the very thoughts of those that wore them

Would the Elves of Erigion have turned to Wraiths if they hadn't had foiled his plan?

Seeing that the marring of Melkor accelerates the phisical fading of the elves and that Sauron's victory would have deepened that marring, you are at least partially correct.

Sauron didnt know anything about the 3 rings, but was it through their power that Celebrimbor perceived of Saurons' plot?

Probably yes; after they perceived him and his designs, they took off their rings.

If Aragon or Gandalf had put on the One ring during the books, what exactly could they have used it for?

It is possible that Gandalf would have mastered the ring, but then:

Originally Posted by Letter #246

the Ring and all its works would have endured. It would have been the master in the end. Gandalf as Ring-Lord would have been far worse than Sauron

If Sauron had recaptured the One Ring would he have commaned the wearers of the Three or just have access to their power\workings?

He would have comanded everything, forever:

Originally Posted by The last debate, RotK

If he regains it, your valour is vain, and his victory will be swift and complete: so complete that none can foresee the end of it while this world lasts