Was Numenor different than Middle-Earth?
 

Did it have a ethereal and timeless feeling like Rivendell and Lothlorien? Was the fauna and nature landscape of Numenor closer to Valinor since it got branch from the blessed land, like the White tree?

I would say yes, to a point.

Being the most westerly of mortal lands, in fact being in sight of Eressëa, had to have had some effect.

Elvish visitors noted that, in its bliss, Númenor in parts was almost as fair as Eressëa itself. I think Men from Middle-earth taken there might have felt that they were in the Blessed Realm. That makes the eventual Fall even more tragic, maybe. :(