Little late for a reaction, but I
may be able to help you with your second question:
The other issue, I try to assign a material to any object, but the dialog box that appears to me should have a listing of available materials is empty.
, You mean the dialog box 'Material' in WED? And are you working with several .c (/script) files? If so maybe add this line to your main .c script file:
, I quess you can choose the material now from the dialog box.