In a .44 Magnum revolver, yes. In a semi-automatic .44 Magnum (such as the Desert Eagle), no.
NO
44 magnum and 44 special.
No, they can not, do not attempt to mix real ammunition in airsoft guns.
There's a .44 Magnum variant of the Desert Eagle.
Images of a 44 Magnum Revolver can be found online. Image hosting sites like Photobucket and Shutterstock carry photographs of 44 Magnum Revolvers from different firearm manufacturers.
No. While Dan Wesson DID make a .44 Magnum revolver, it was not known as a Desert Eagle. IMI made a .44 magnum Desert Eagle Auto pistol, but not a revolver.
100-400 USD
Depends on what ammo and what you mean by "stronger".
A Smith & Wesson .44 Magnum revolver.
Yes, .44 Russian and .44 Special can be fired safely from a .44 Magnum revolver. They are the same diameter, shorter, with less power. Also darned hard to find and expensive.
You need the services of a trained professional