Galadriel's

[Gorthaur the Cruel]

Couldn't she have had full knowledge that her efforts would ultimately be futile, yet still mourn for the moment when it came?
This has gotten a bit off course, going from the question of whether Lórien's beauty and healing properties were mainly the results of the Elessar's powers, or of Narya's, to the merits of the effort itself to create a Valinor in miniature. I take the blame for getting things off track. Perhaps this question deserves a thread of its own.

A thread of its own, indeed.

But what would she mourn if all was wrought out of futility? If all her endeavors paled in comparison to the real thing, why mourn the moment of loss? Why would she mourn losing Lórien if her heart's desire was to Valinor? Remember what she said to Celebrimbor or Gandalf in U.T., that she wished for trees and grass that do not die. Did not Nenya afford her this power? There was no stain, decay, or deformity in Lórien, so why would you say Galadriel was disatisfied because it did not match the real thing? And if her creations with Nenya she deemed futile (as you suggest), why lust over the One? Because this was the only way to save Lórien, right? Of course, if she wanted to save Lórien, it must mean that she loved it and did not regret or considered it of lower in quality compared to the West (as you also suggest). Hence, her regret, I believe, truly stems from Nenya being bound to the One. Since she rejects the One, she helps bring about the end of Nenya. There's the futility.