“if they build the airport near base, then S.R. won’t be a good place anymore.”
That may or may not be true, but as far as airplane noise goes, there would be very little, even in the southernmost parts. From the northern parts of Scripps Ranch, and probably from the middle parts, you wouldn’t hear them at all.
As far as the other effects, such as traffic and congestion, that may be a different story, but I don’t know. It doesn’t seem to me like traffic around Lindbergh is exacerbated too much by Lindbergh being there. And, from what I hear, there would be freeway expansion projects if they put an airport there. That right there would worry more than anything else. Freeway expansion takes a long time and is a real hassle.
All that said, again, chances are very slim of an airport being put there.