[Gorthaur the Cruel]

Also, Saruman's ring didn't appear to have any power, seemed as if it was a failed attempt of creating what Sauron created. So, even if the One Ring did have control over Sarumans, it wouldn't have really mattered.

Wrong Boromir. Saruman's Ring enabled him to breed an enhanced version of orcs - the Urukhai.

The thing is, Sauron forged the One Ring after the Three were forged. And after the Nine and the Seven, for that matter. He had already ideas for domination through instructing the Elves in this craft and his plans came to fulfilment when he made the One Ring in Orodruin.

Did he really forge the One after knowing the existance of the Three? I doubt it. Didn't Celebrimbor forge the Three in secret, & Sauron even left before they could be completed.

What I'm wondering, though, is what would happen if the Elves made another Three after Sauron's complete destruction. Would they be able to regain what was lost when the Three lost their power? They probably wouldn't have done that, though, even if they thought of it, and even if any Elf still lived that knew how, afraid that another Sauron would come along and just make another One.

I don't think that the Elves would be capable of making another Three (even if Celebrimbor had been alive). These things are like the Silmarills. You can only make them once, but you can never make their like again, just like how Feanor feels about his Silmarills. It would be nice though if it were possible for the Elves. Such a sad fate for them.