the texture id is the number assigned to the dds file in 3dtexture .... that number represents the coloring and look of your robot .... the effect id would be the id assigned to the c3 files that represents the shape movement and mesh that dds file goes to
yes they can be whatever u like but they have to represent the number on the actual files or they will not display anything at all
suggestion ... get another weapon with all of the supporting files included and then change the ids to whatever your new weapons filenames are or at least point them to the new ones