1) That's not true at all, there is even an accessory detailing the Outlands.
...You mean the CD? Because that thing is super fun, but not... what's the word... oh. Useful.
And it's still just about isolated enclaves on the low-detail poster map that came in the original boxed set.
Seriously, why a ring of gatetowns? The Outlands are supposed to be infinite, so why is there a border of gatetowns an arbitrary radius from the Spire? What's beyond the ring? Does anyone bother going out there? Why would you?
Put the gatetowns on floating islands. Let them drift on paths determined by the will of the cosmos.
Also, spelljammers docking at Sigil's inner ring is an awesome image.
Hey, I wanted a Sigil and the Outlands boxed set as much as anyone, but it never happened. IT'S ASTRAL SEA TIME.
2) Never been redundant, the Ethereal plane is where other planes are born, the elements, ideas, dreamscapes exist, etc, nothing like the Astral.
Going to have to completely disagree with you here. Two transitive planes. One has githyanki pirates, fortresses built on the corpses of dead gods, astral goddamn dreadnoughts, and oh, yes, /action/. The other has purple haze, skeletal platypi, and THIS GUY:
http://www.wizards.com/dnd/images/MM35_gallery/MM35_PG104.jpg
I know which one captures /my/ imagination.
The ethereal exists exclusively to contain demiplanes. It's the cosmological greasy newspaper wrapped around the fish and chips. And there's no reason why we couldn't just put the demiplanes in the Astral (or in any plane to which they were tangentially related).
Some speculate the Demi-Plane of Dread/Ravenloft (a demi-plane deep in the Ethereal) could one day become an Outer Plane.