Yep Dirk it's working out fine.  In non addon airports I just keep FSA DISABLED, and can ENABLE when flying out of addon airports.  I am stumped about how one can [quickly!] chose a SID from Skyvector.com.  Departing at large terminals can mean 12 SIDs to chose from w/ names that don't mean anything to the uninitiated!  I haven't even dealt w STARs yet.

I'm confused as to why you would need to disable FSAD at all. The airport information your aircraft's FMS uses is all based on Navigraph data. It doesn't care what airports you have installed in the scenery. FSAD includes approach data for runways that might not exist in a default FS airport but the same issue occurs with updated FMS data as well.

 

Also the default ATC will not assign approaches to one of the nonexistant runways.

I guess you're right--for some reason since disabling FSAD I have yet to be routed into a runway that doesn't exist--which must be a red herring, whereas it was becoming the norm with FSAD enabled.  No worries I will live with it until I upgrade P3D at which point I will keep the oem nav data and live with it.  I got in deeper than I should have and certainly w/ STARs, for how I use P3D, it's just not worth teasing thru 12 STARs w/ names that don't relate to anything to give a clue which STAR should be used upon arrival in a big terminal.   I still need to read about how real world pilots figure that out.  I see at Skyvector.com the list of STARS is prodigious in the larger terminals and right now the best I can do is open up each .pdf and try to tease thru what makes sense.   It's just not worth it for pretend pilotage!