I think you should familiarize yourself with the things SGDK2 can do easily before moving on to things it won't help you do (and will be harder). SGDK2 is designed to help you make huge scrolling games without huge amounts of effort. If you want to make other types of games for which SGDK2 wasn't designed, be prepared to do a lot of work on your own. That is, of course, unless you don't want to make games but just want to continue expanding the repertoire of what SGDK2 can easily do. But then you have to take responsibility for doing the work and not ask others to be doing it for you
. We can answer specific questions on certain points, but you're asking a huge question here. I can try to answer your question in general terms, but it might not help much. First of all, I would not recommend using C++ when C# would be much easier to integrate with SGDK2. Secondly, the Display object in the SGDK2 default project source code exposes a device property, which is the Direct3D device object. You can use that the same way any other Direct3D application would. And finally, to gain more control over the drawing of the scene, you may have to edit the GameForm.cs file which draws the 2D layers -- you could tell it to draw something besides 2D layers, but then it's up to you to write all the code for defining and drawing the 3D objects. The IDE does not have any 3D designers in it.
It would be kind of cool if you could design the map in 2D and then when you run the game, walk through it in 3D.
