Sorry, I have been away and busy.
1) materials.lma.lua can be downloaded from here:
http://en.wiki.eagle.ru/w/images/0/04/FilesHelpLand.rar
2) .rn files are things that you can not see (Splines to designate runway location, splines to designate taxi paths, dummy placeholders for models, splines for taxiway/ runway lights.
.sup file is for things that you can see (runway texture, taxiway texture, taxilines, etc)
Send me a link to the file if you want me to try to split it up. I am quite busy though but will try to help :)
3) Second part is true. As long as the pivot point of the model matches up with the pivot point of the square plane, you will be ok. To be more technical, the pivot point of the model will ALWAYS align to the pivot point of the placeholder plane.
4a) FC2 scenes file was probably created using a newer version of plugins that the public ones cannot import. You will need to import FC1 scene files for reference.
4b) Assemble scenes does not work? Does it specify what files are not found?
5) Not sure
6a) Not sure about spawn locations
6b) You must compile all files into a .scn file using assemblescenes.exe before it will work.
Try this:
http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=12567786&linkID=9241177