A way into professional coding?

Blitz3D SDK Forums/Blitz3D SDK Programming/A way into professional coding?

I would say its a good start. As you said, a lot of studios use a graphics engine. We use Renderware and is that so much removed from B3DSDK? :)
If you can show you can manipulate the geometry well and show you have an understanding of the underlying transformations, verts, normals and other such associated concepts, then you should be able to get your foot on the first step of the ladder. There is no way a studio would expect a newbie coder to know something like Renderware, as the cost is very high and is usually only available to developers, not hobbyists.