Depends, are you talking free or paying for. It depends on who it is downloaded from.
Yes, you can get a Dash-8 in Microsoft Flight Simulator 2004 by downloading a Dash-8 add-on. Just type "Flight Simulator 2004 Dash-8" into a search engine.
No, Microsoft Flight Simulator 2004 add-on aircraft cannot be transferred to Microsoft Flight Simulator X.
No. On Flight Simulator, you fly planes, which is why it is called Flight Simulator, and has planes on the cover.
It is exactly what the name states, it is a flight simulator, it is as realistic as you can get (besides Microsoft Flight Simulator X).
Yes, you can download add-ons for Microsoft Flight Simulator 2004.
To open aircraft doors in Microsoft Flight Simulator 2004, press: Shift + E.
Yes, you can play Microsoft Flight Simulator 2004 without a disc. I have put a link under this question explaining how to play Microsoft Flight Simulator 2004 without a disc. I have put a link instead of explaning how to do this because of the amount of steps.
You can't, the coding on the planes is different. Most of the planes you find in Microsoft Flight Simulator 2004 are available in Microsoft Flight Simulator X.
You cannot play Microsoft Flight Simulator 2004 anywhere online. One, it would be illegal, and two, it needs to be installed on your computer.
You cannot download Microsoft Flight Simulator 2004, you have to buy it.
MS Flight Simulator(2004 or 2006) is required to use FS Fighter Pilot add on?
you wont get it muhahaha