The other guys answered 1 and 2 pretty well, so I'll say something about 3.
CA isn't just about driving a single unit around, although you can. You control the entire ground battle in more of an RTS type of game play. Order group movements. Set artillery strikes. etc.
The ability to have a human JTAC(s) is also often overlooked.
If your sitting in a TOR or other air defense unit you are not as inferior as you might think. Limit your radar time. Use shoot and scoot tactics. You can clear the skies of other players if you know what you're doing.
Welcome, and Good Luck.