I believe your source is right. That antenna cable is part of the aircraft, and part of the model, so changing it won't be easy.
-SNIP-
As for parking space that is what AFCAD is for just change the parking spaces at the airports you want. You can edit the aircraft cfg file to make it possible to park any any place you want
Using AFCAD to modify parking size/designations worked well with FS9 but no so with
FSX. You can use AFCAD to change size in FSX but you will most likely start running
into some other unexpected problems unless you go about it in a very structured way.
You'll need to convert6 the AFCAD to XML, along with the original airport data from
the FSX files. Edit and merge the two then recompile to a BGL.
As to designating parking spots by airline codes that worked in FS9, I believe
I read somewhere that that doesn't work in FSX.
Best to check in on one of the scenery design forums and get help from the
experts.
Paul