Quote: "I now got a badly textured "red" ball that acts like a minigun."
wich is a good start.^^
when it should be used as a ball, look into the scifi stock "alien-artifact"-fpe. thats a dynamic ball with physics on. you may look through the items inside fpsc-editor and pick some reference entities. i did a copy outside fpsc-folders for me with examples for weapons, static enviroment, character, animated things etc.
files you have to create:
.x model
.fpe controller
.dds/.tga texture (with different maps if you want to use shading effects, I/U/D2/D/...)
(.bmp thumbnail if it should be shown in the editor-browser)
the fpe tolds fpsc how to handle model & texture. did you uv-map the model and create a .dds/.tga as texturefile (same folder or texturebank, linked to the model inside the fpe)?