Regards MS Flight Sim x Deluxe - has it got IFR panels such as the Cessna Skyhawk IFR panel?
Yes. but not Cessna Skyhawk , you need to download that plane from the avsim.
What ATC features are available? Can one file an IFR flight plan en-route?
Default Atc is available which is good, and you can create and IFR flight plane.
How can one record videos and save as mpeg for playback with this version?
use Fraps.
What system spec do you reckon is ideal for optimal performance? Have you got this system spec?
you need a dual core Cpu with 2mb L2 , a nvidia 6 or a ati x1800 and above series Graphic card and a 2 gb ram.
Hope this helps.