Check out this PDF provided by valve: http://media.steampowered.com/apps/dota2/workshop/Dota2ShaderMaskGuide.pdf

Yeah sorry about that. I do have a friend (Sith Happens) who does some z-brush streaming. Perhaps when he has his stream up I can make an announcement...

As long as the head verts are all connected (and not connected with anything else), you can select all of it by hovering your cursor over a head vertex and pressing "L". As for z-Brush, you're out of luck: I've never used it before.

Some items allow bigger textures, but really it's about prioritizing and optimizing. I wouldn't be surprised if all of those feathers used the exact same UVs (you can overlap uvs for symmetrical parts). Any high detail parts should take up larger space on the UVs. I don't really know how else to explain it.

It could look good even without the blood I think. You could remove it, or just simply making the blood less "neat"-- kind of like this image.

Your description of "wrong" seems to be related to one of two things:

1) Your normals may not be facing the correct way.
2) There might be a problem with the alpha channel of your _color texture.

3D Models are composed of many small triangles, as you know. These triangles normally can only be textured on one side (this is mainly the case for the Source engine). Thus certain polygons on the model may have their normals backwards; that is, the texture is facing inwards towards the center of the model rather than towards the outside. The resulting 'face' seen from the outside is invisible. To fix this problem, you can recalculate your normals (either manually or automatically).

Automatically: Select your model, go into edit mode, navigate to the "Normals:" subheading in Mesh Tools toolbar (on the right-- press "t" if you can't see it), click "Recalculate".

Manually: Select a portion of your model in edit mode (such as an affected polygon), navigate to the same menu as above and click "Flip Direction" to manually flip the normals of just the selected faces.

To check to see which faces have inverted normals, you can change the viewport to showing the Textured model instead of the Solid. Check out this picture.[dl.dropbox.com]

In modeling, the alpha channel of your base texture is usually reserved for alpha transparency. This is true for Dota 2. Thus if you want portions of your model to be transparent, you can use this channel to your advantage. If you don't want transparency, simple save your _color.tga texture as a 24bit tga file to remove the alpha channel.

I hope all of this helps. Good luck.

Glad it worked.

Looks good, although what were you trying to go for with the red outline? If you were trying to make it look like blood, it didn't turn out so well... Otherwise it looks ok.

If nothing else works, take your _color texture and save it as a 24bit .tga file. This ensures that it doesn't have an alpha channel. The alpha channel of the _color texture controls transparency. It might be causing the issue. So either remove the alpha channel from the _color texture or just save it as a 24bit file (instead of 32bit).

You don't need to rename your .smd file, only the output filename (check this picture[dl.dropbox.com]).

If you are sure that you recalculated your normals correctly, I'm not sure what could be the problem. It may have something to do with the shaders. I'll look into that pdf file to see what could be the issue.