Re: Tolkien Elves in Hero
I'd say Galadriel, Elrond and all were more powerful by the end of the Third Age because of their long years of experience, although the rings helped. I don't think the Elves had waned much until Sauron was defeated, although the process may have started. Celeborn at least remained in Middle-earth for a while, as did Cirdan.
Sauron was no longer staying in Dol Guldur during the War of the Ring, although it was still one of his major strongholds. I think it was commanded by Khamul (second of the Nazgul), although he was in Barad Dur when it fell.