I would make
creature oriented, since most of Aether from permanent control anyways. IE Dim Shield, Silence, Immaterial.
I would also make
creature oriented. I think making more use of flooding could help the card see more play besides with afl, flood combo.
Gravity, I see as direct player interaction. Gravity pull, catapult.
Entropy is player is balanced, so that's more of a preference on your part. I can see more creature interaction than anything.
Air is defiantly more creature friendly.
And that leaves fire. Maybe fire should have some sort of damaging effect?
Just some thoughts.
(edit, read through and accidentally posted stone skin under gravity ^^)