The editor can usually take a pretty good guess at what texture names mean, and automatically generate a material file. However, I can't comment on your situation specifically without seeing the actual files.
It's early in development to comment on that. The back-end is done, but the front-end typically takes 3-4 times as much work, and we do not yet know exactly what effects we will implement.
Thanks, I updated the code sample.
The problem is you are rendering the world after drawing text, which clears the color buffer. Render the text after drawing the world instead.