I really appreciate all of the responses, truly.
That said, as a newb who hasn't been in a real cockpit for 15 years--there's a lot of stuff thrown into those answers that have me suffering from a touch of information overload. So, let me ask this a little differently.
1. How do I keep from angering the ATC and other pilots when I'm flying out of/in to places, considering I'm using vanilla FSX:SE, with respect to IFR Flight Plans? (Sounds like "/a" is a solid go-to, and just plan through FSX?)
2. I like the idea of a higher-end pay-for plane, but I don't think I can justify that just yet, having just returned. Perhaps in a couple of months. That said, anything particular to look for?
3. I tried installing the stuff from aero.sors.fr, and a couple of things happened. First, got some scenery errors. I worked through those, and loaded up at KMEM (I have a SID printed out for that, so I had a few intersections I could look for). I didn't find any of the intersections. Any way to tell if the install worked, and these simply weren't there, or they're there, but the install failed?
4. With that in mind--did I understand that response correctly? It effectively inserts the newer fixes, intersections, etc?
Thanks a ton. I don't want to wear-out my welcome with the newbie questions, but this feels sort of...well...basal for the whole system.