Dependencies: Blender, Blender Source Tools, Source FilmMaker, Windows.
Additional dependencies for these instructions: Notepad++, VTFEdit (later).
Useful QC commands: https://developer.valvesoftware.com/wiki/Category:QC_Commands, although I'll tell you all you need to know for now.

- First thing you wanna do is open Notepad++, go to Plugins > Plugin Manager > Show Plugin Manager, find "NppExec", tick it on, install it, and reboot Notepad++ (though you can close it for now).
- In Blender, select the armature, go to pose mode, and make sure the vertices of the mesh move around with the bones of the armature. If you haven't done that, look up a tutorial on weight-painting/rigging for Blender.
- Select the mesh(es) you want to export, go to the scene properties, configure it like http://sta.sh/013zscme7uoj and try exporting. (Click "Export", then choose the files you want to export.) It will export to the export directory chosen, with the file names of the Blender object names (or group names, if things are grouped together).
- If you get an error about too many weights, you can set the "Weight Link Cull" to 1, or use SMD instead. Just make sure to keep the Blender session saved somewhere! If you plan on using flexes ("shape keys" in Blender) at any point, I recommend DMX.
- Now you can go back to Notepad++. Copy-paste the following:Edit the X-es as you wish. $ModelName refers to the model location (for example "player/scout.mdl" for the Scout in Team Fortress 2. The X in $Body refers to the internal name (basically unused, just use "Body"). The Y in $Body refers to the SMD or DMX file to load (for example "Scout.dmx", with the extensions optional). $Sequence is just something important. Just direct the X to the same file as $Body is using. $CDMaterials is where the materials are expected to be (for example "models/player/scout" for the Scout). The materials themselves use the same names as the materials assigned in Blender. (Can provide an image if requested.)
- Save that file together with your DMX or SMD file(s), and call it whatever you want (for example "Scout.qc"), as long as you make sure the extension is QC, not QC.TXT or anything like that.
- Now press F6 in Notepad++ with that QC file still open. You should get a little "Execute..." box pop-up. In that box, copy-paste the following:Now click OK. That command will be saved for the next time you want to use it. This uses the QC to compile the DMXes/SMDs into a Source model file. If you get any errors, copy-paste them from the console thing at the bottom of Notepad++, so I can look at them.
- Launch Source FilmMaker, but choose "Open SDK" instead of "Launch Source Filmmaker". Now click "Model Viewer", and go to File > Load Model..., and browse to "usermod" of Source FilmMaker's directory, then go to models and whatever you put as $ModelName. If everything has gone good, you should now get your model... except pink-black checkered.

Tell me when you've done this, and I will go to the texturing part.

Check the console in Source, see if it either can't find the materials or it can't find the textures, and place and name the materials and textures where Source expects them to be.

That doesn't answer my questions.

If I understand you right, yes, I think.

In Source FilmMaker, lock the root bone (typically the pelvis bone), then use the Zero preset on rootTransform, unlock the root bone, and re-export the animation.

By exporting using the Blender Source Tools, probably.

No, it asks for SMD/DMX, not OBJ.

Define "TF2 Workshop", please. In the Source SDK? Outdated, don't use that. In Team Fortress 2? No, it asks for SMD/DMX.

引用自 Keepon：

Is there even option in clean Blender to split shapekeys in half

I don't think so.

In that case... Check the console (in Source) for errors, regarding missing materials or not being able to load this or that texture as it doesn't exist.

A few trouble-shooting hints:
Are you using $CDMaterials in the QC, and are the materials in said folder?
Do you say texture name (scout_blue) in the materials, or path and texture name (models/player/scout_blue)? (You should use path and texture name.)
How much do the textures fill? (Source doesn't read textures above 64 megabytes or such.)