It is salvageable but the complaints listed need addressing, particularly strat hardness.
I was pulling so hard for the Bishops to win last night to put us out of our collective misery.
You can salvage the terrain by hand somewhat like the terrain builder has subsequently adjusted the general cross sectional shape of the spiral arms. Along with adding more clutter tile painting to add trees and grass. Flattening or elevation reduction can be done to the center of the terrain but, someone has to spend hours manually doing that. It is simpler to take the lessons learned from this terrain and use them to guide you or another in what not to do with a terrain design. A cross spiral arm water ring completely around the terrain would have been helpful.
Live and learn and hope some players are currently working up some new MA terrains. I don't know if the current heightmap file can be pulled into L3DT, reworked, exported and imported into the terrain editor and not effect the objects and clutter tile painting. Even if it can, that is someone spending hours in a program when those hours would be better served bringing new terrains to the MA.
And strat hardness, you know Hitech's bribe, but not if he will budge on the strat issue.