Idea: Looking for unforeseen consequences

[Gildedragon]

What if the Ethereal as a transitive plane was dropped and one fused the Ethereal and Incorporeal rules into 1 single set.
The Ethereal is still "there" but it is just a way of relating to whatever plane one is on...
Any consequences of this spring to mind?

I don't see how it would affect planar travel since in 3.5 the Astral links the inner outer and material planes

[Falcon X]

Did 3.5 change it so the Astral borders the inner planes? Back in 2e they kept them separate.

What you are getting at sounds a bit more like classic, non-D&D concepts of an Astral plane. Read Shadowrun's take on it.
As a whole, it will change the cosmology a little, but nothing you can't hand wave. It depends on how you use it.
In your setting:
- Do githyanki stare in at humanity as if through a glass pane?
- Do you travel through this space at speed of thought, or how you would on the ethereal?
- Do the elements from the inner planes start affecting the Astral conduits.
- what happens if you are Astral projecting and run into the Plane of fire? Does it burn up your spirit form?

[Gildedragon]

Did 3.5 change it so the Astral borders the inner planes? Back in 2e they kept them separate.

What you are getting at sounds a bit more like classic, non-D&D concepts of an Astral plane. Read Shadowrun's take on it.
As a whole, it will change the cosmology a little, but nothing you can't hand wave. It depends on how you use it.
In your setting:
- Do githyanki stare in at humanity as if through a glass pane?
- Do you travel through this space at speed of thought, or how you would on the ethereal?
- Do the elements from the inner planes start affecting the Astral conduits.
- what happens if you are Astral projecting and run into the Plane of fire? Does it burn up your spirit form?

I'd not touch the Astral plane at all. That would work as standard.

Going ethereal would be the same as going incorporeal. I'd have to smooth out the differences between both descriptors (like picking whether creatures can go all the way through a solid object or not, I'd say "Yes")

[daremetoidareyo]

Makes sense to me. You can wrap the plane of shadow into it too to get rid of that undeveloped mess also.