brettt777,
Earlier models that worked fine in FS2000/FS2002 (even when imported from CFS2) won't show up well in FS9, as many of the animations are handled differently. This is why the moving parts tend not to show up: fan blades, undercarriage etc.
You'll find that aircraft specifically designed for FS9 using GMAX or FSDS (and there are very many available, including the combat types) will work fine - just look in the downloads pages here to get an idea.
You can't decompile a MDL file using GMAX, or any other program that I'm aware of - and a good thing too, or else no aircraft designer's work would be sacred, and nobody would then bother designing new models if others could then easily decompile and modify their work.
