Is there any public API that grants access to the Dust 514 market data, or the game object data: dropsuit stats, weapon stats, equipment stats, vehicle stats, etc.?

You can lookup market data. Just amount of each items sold.

For this you actually end up using the EVE CREST MarketHistory endpoint located here

For game data look at the DUST514 SDE here.

If you want to see how to use the SDE, take a look at my sde package here
The package uses encoded binary dumps of the SDE struct that is generated using this
It's written in Go, but it should be fairly readable even if you don't know the language.

Just awesome! Had some fun with the data this evening. Thanks, THUNDERGROOVE!

Is there any graphics data at our disposal - raster images, 3d files?

For instance, where did the boys at protofits.com acquire their images?

All of the images come from what is called the Image Export Collection(IEC) from EVE here

What you would want would be the types zip. You would find the TypeID of the item you want and lookup the file in the following format {TypeID}_{Size}.png

So if you wanted the icon for an Amarr Assault ak.0 you would find it at 364022_64.png

Of course this is only an icon, but it's what we get as poor dusties when it comes to development resources.