Gosh, I've been away from FSX for 4 years now! Forgot stuff.

Cheeks wrote:

For 1.
http://www.flight1.com/products.asp?product=utrafficfsx
OR
http://www.world-of-ai.com/

The first one is payware and installs all of the different airlines at once, so it's pretty much for the lazy people I suppose, the second link is freeware, but has better quality packages, however, you must install one at a time.

For 2.
http://www.turbinesoundstudios.com/

You do NOT need to look elsewhere, they have by far the best sound packages for FSX, without doubt. I absolutely LOVE them!

For 3.
I'm not too sure about a particular addon other than FS Passengers, however each particular aircraft may have something like that added to it, for example, the LevelD 767 has F/A sounds.

Hope that helps!