My problem with the slave mining is this
Wouldnt it be easier to simply make machines that mine? They wouldnt need to rest and wouldnt rebel. Also a race that has the ability to traverse the universe would be beyond the need to mine gold. If for some reason they werent then im sure they would have a grasp on manipulating matter and could create their own.
edit on 2-11-2011 by Jassu because: (no reason given)