No BD! He's not worth it!
I don't know. On the one hand, it would be nice to see Umbra done right again. But on the other hand, I despise Umbra both as a set and as a character.
If you do do him, either give him catterpillar (sp?) treads, or build his feet so they obscure his wheels. 'Kay?
EDIT: Also, there's some unanswered questions in your Q&A entry