Couple of things:
1) To define what textures go on what faces, you adjust the material name of the material (capitalization does not matter) applied to a face of the model.
GIFYou can have multiple materials per mesh, and assign them on a per-face basis. This means you dont need a single mesh object for every different color you want to include in a model. Me giving the material a color was optional - its just to show it better in blender. Ports exporter has an option to auto-export 16x16 png material images based on the materials assigned to the faces, though.
To quickly join mesh objects together, select each one of them and do ctrl-j with the mouse hovering over the 3d view. this will combine all the meshes (and any materials) into the last selected mesh object.
GIF. I also show you how to change the rendering mode - I did that in the last gif but didn't show it.
2)
I probably should have uploaded this earlier, but here's a positioning reference model you can use for Hatmod specifically. Import the .obj into whatever file you need it in. I forgot I had it lol.
After repositioning and rescaling your model relative to the head, ctrl-a apply location/rotation/scale.
Here's a gif of me doing it, but I'm pretty sure you know how to do this already.
