It depends on where you download it from...
If you have bought it and are downloading from the Microsoft website, then it is safe.
If not, there is a chance it may a have a virus.
Again, it really depends on where you get it from.
You can get more aircraft in Microsoft Flight Simulator X by buying/downloading expansion packs or by buying/downloading specific aircraft.
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.
Depends, are you talking free or paying for. It depends on who it is downloaded from.
No, Combat Flight Simulator 3 does not need a Flight Simulator.
There is no need to buy Microsoft Flight Simulator X: Deluxe Edition as Microsoft Flight Simulator X: Acceleration contains everything from Microsoft Flight Simulator X: Deluxe Edition and more.
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).
No they are different
No, Microsoft Flight Simulator 2004 add-on aircraft cannot be transferred to Microsoft Flight Simulator X.
No, you cannot use the add-ons for Microsoft Flight Simulator 98 in Microsoft Flight Simulator X.
Flight Simulator X is by Microsoft, the full name is Microsoft Flight Simulator X.
Microsoft Flight Simulator X: 18 Microsoft Flight Simulator X: Deluxe Edition: 22 Microsoft Flight Simulator X: Acceleration (add-on): 25 Microsoft Flight Simulator X: Gold Edition: 25