Can we run Biodiesel or Vegetable oil in our Duromax? If so, what do we have to do? Does it effect the warranty?

yes, at least biodiesel. I haven't tried SVO but don't plan to. i would prefer to run B20 over regular diesel due to the added lubricity.
Here read this link:
http://www.dieselplace.com/forum/attachment.php?attachmentid=44499&d=1188575783
The discussion is in a sticky in the Maintenance & Fluids section of this forum.

Thank you.