Adding a terminal is relatively easy; you could use something like the airport software – see here:
http://www.airportforwindows.com/
Don’t be fooled by the front page – it is for FS2004 as well.

As for removing things, well I think you’ll achieve that by creating an exclude file.

There is a UK scenery Yahoo! list with people on it who could help further. I can give you more details if you like.