So, if i understand this logic, the Nevernever is basically a crossroads nexus where each part of it can lead to a different place/dimension. Cool concept.
Close. It's not so much a nexus of dimensions as it is the single infinite dimension of wierdness that itself includes all of those 'different places' jutting up against each other.
The 'nexus', from a humanocentric view, would probably be Faerie, because that's, usually, the closest place in the Nevernever to a given place in the mortal world, forcing most mortal practitioners to travel to whatever destination in the Nevernever by first stepping into Faerie (again, usually; there are, obviously, places in the mortal world where stepping into the Nevernever would take you to someplace other than Faerie).