Ok I was trying to remember offically how portals and such work well in partiucular where they can go to and from. For example can the outer planes have portals directly to the elemental planes? I mean spells out there that summon elementals I know can't reach the inner planes so they instead grab local material to form them. One of the most common exmaples I can remember is the Abyss summoning a water elemental is going to summon a blood elemental instead.
But anyway can you do outer plane to inner plane portals offically? Also can Astral conduits reach to the inner planes I know that they certainly reach the outer planes and prime material planes but do they go directly to the ethereal or inner planes?
Finally I have been thinking as I thought about this problem about using the blink spell on the outer planes can the caster actually use this spell effectivily ? (They blink from their location to the Ethereal which obviously touches the prime where the spell effect was written for).
P.S. Really finally this time I allowed a person that cast blink who was a native of the ethereal plane to move at full speed rather than simply 3/4 like in the Players Handbook because the descrition of the spell there says this is because they can only move half speed in the ethereal which as my player pointed out didn't seem to make sense for his character.
Ah well a few things to chew on 
Like gate spells, but they come in a lot more shapes and forms, and usually require keys.
Yes. There are numerous examples of this in On Hallowed Ground and The Inner Planes. For example, there's a portal from the Paraelemental Plane of Ice to the Abyss, and a portal from Garl Glittergold's realm to the Elemental Plane of Earth. Not to mention all the thousands of portals from Sigil to the inner planes.
No, not in the Planescape cosmology. The Astral only touches the Material and Outer Planes, and its conduits only connect the Material Plane to the Outer Planes. Astral conduits are like the silver cords connecting an Astrally travelling character with her body on the Pirme, except the Outer Planes are the astral form and the Material Plane is the body.
There are other conduits, called planar conduits, that connect parts of the Outer Planes with other parts of the Outer Planes, but these are thought to have been regular astral conduits that have shifted due to some cosmic accident or change in the location of various outer planar realms.
Inner Planes are connected to the Material Plane by elemental vortices, which are like spiralling storms channeling elemental material to places of great elemental concentration on the Material Plane. They're a completely different phenomenon, probably more like digestive tubes than silver cords. Elemental vortices don't reach the Outer Planes, which have no true elements.
The difference between vortices and astral conduits on the one hand and portals on the other is that vortices and conduits form naturally, reaching between the material plane and those planes nearest to it. Portals are artificial to one degree or another, and can go wherever their creator wills it. The origin of the portals in the Outlands gate-towns is unknown, but they seem too elaborate to be entirely natural. In any case, they only join adjacent planes.
In other cosmological structures a DM might come up with, there might not be such limitations.
I'd require a spell key.