Ok, that video was OLD. I am trying to use these steps to no avail in Blender, it is late and after a couple hours I'll have to surrender until the morning.
Please let me know if there is a better way.
A little guide to export a .cgf with proxy out of blender:
As soon as you got your model and your proxy mesh, you uv map your object (the proxy doesn't need a UV map. CryBlend adds a default UV map when exporting).
Then parent your proxy to your object (doesn't have to be done, but it's cleaner).
Now select both, your object and your proxy. Open the CryBlend menu and klick "Apply All Transformations".
Next, you want to add an export node. With both (object and proxy) still selected, go to the cryblend menu and add an export node.
Give it a name. For example name it "Croissant".
Now you need to setup the materials for export.
Go to your object and add one material with the following name:
The first word is the name of the export node. The second part is the material number (first material is 001, second is 002, third is 003 and so on. This means, that you just count up this number for every material). The next part is the name of the material. Here you are free to choose any name you want. The last part is the physics information.
We choose physNone for our object, because we want the proxy to be physicallized. Not the actual object.
Now we setup the material for our proxy. Name it:
Again, we first have the name of the export node, then the material id, then the material name (could be any name you want. You could also call it "bwebrefserf" and it would be okay. And the last part is the physics information. This time we choose physProxyNoDraw. This makes it a proxy.
Now you go to cryblend and hit "Export to game". Should be done now.
By the way: blender exports .tif with deflate compression. RC is not amused when getting a compressed .tif.
So if you want to export your texturemaps out of blender, just export them, then open them in GIMP or Photoshop. And save them as uncompressed .tif.