From the way you wrote this, I think you may be chasing a myth like El Dorado or The Fountain of Youth. The English may come as close as anything to fitting the bill though. White usually has a safe king, a slight but safe advantage, fluid play and few or no bad pieces or weak pawns.
open to unique openings
If ever there were an opening,simple but very effective, on which to rely; please share. AND by the way, by very effective: i mean to say impregnable, yet...fluid.
The Stonewall would be impregnable...almost. It's not fluid nor fast. Perhaps study strong pawn structures, like the Stonewall (a2, b2, c3, d4, e3, f4, g2, h2) to see which one you like best, then develop your pieces around that structure, changing the move order when necessary as play proceeds to get your desired opening.
If ever there were an opening,simple but very effective, on which to rely; please share. AND by the way, by very effective: i mean to say impregnable, yet...fluid.