Jack, setting the height and width of the editor doesn't require a recompile.
This is defined in the user control (.ascx) file which is calls the eidtor. In the case of DNN it would be in the user control file of the module that is being loaded. You can change this, save the file and it will be updated automatically.
You have to remember that the editor can only integrate with DNN using the properties of the provider that the dnn developers themselves set. Its not the job of the editor code to over-ride these.
In terms of settings the background colour of the editor, it would be nice to have a property which could be set to do this, which Adam has stated will be added to the next minor version.
I don't think a css file is the place to set them though. All other settings related to the editor are placed either in the provider or .config files, which I imagine is where this setting will go too.
Cheers,
A