If you really want to remake Greenrun to the max I think you first need T4M for that.
I am not sure if the map is going to hit limits besides T4M but maybe, maybe you are lucky and everything is working fine in waw.
This is not impossible and that also goes for the scripting.
But I am not going to make something like that, it will take a lot of time and I have my own plans for releasing new maps for World at War.
I think there are others around who do like to remake that?
If you want to go safe zone it's best to make it bo3.
I'm experiencing the same thing. This is making it increasingly difficult to message people while posing as a 16 yo girl : ( Please fix NOW!