Somehow TG2 likes obj's better after they have been processed through Poseray, which is a free app.
I'll give a very brief description on how to do it. Basically you work from the left to the right menu bars:
Go to input -> load -> 3D Model -> select your obj
Go to materials -> UV -> weld vertices
Go to materials -> basic texture properties -> load the textures accordingly (in my experience this doesn't work, but you can try)
- if you only see "defaultshader" on the far left you have to convert groups to materials
- to do this go to materials -> rearrange -> groups to materials
Go to groups:
- you should now see a list of materials in the left panel
Go to groups -> faces, vertices & normals -> click on "center origin" + "drop to y=0"
Go to groups -> faces, vertices & normals -> enable "calculate normals" and click on "smooth" to the right (normal sum)
- the value of the calculate normals box should change from 0 to 180
Go to groups -> faces, vertices & normals -> Weld Vertices (keep setting untouched)
Important: press "update" at the top left -> poseray updates the model for all the changes you've made in the materials- and groups-settings
Go to OBJ-output -> choose filename -> enable first 3 options -> click on save -> choose path -> enable first 2 options -> OK
Now your model should be good to go!
Load it in TG2 and go to the parts-shader, then load your textures and alpha's.
Test your file and if it all works then save as tgo (optional).
This is the way how I do it and until now it has always worked, so hopefully you will find this useful

Cheers,
Martin