[@OrkytheOrc] I had never actually thought about carving the runes into your skin to use blood magic that way.  I'm going to say that that would work, but it would consume the blood in the body and so would require being really careful.  I'm thinking that channeling more blood into a rune at one time would make the effect more powerful, but it would have diminishing returns. Using multiple runes would be more efficient for the most part, although you'll still see diminishing returns as you increase the number of runes.  Combining the two methods to best suit the task at hand would be the absolute most efficient way to use blood magic, however.

Also, I would love the help!  I'm not exactly sure what your thoughts for the Orcs were, but I was thinking that they would generally be considered less cultured due to the fact that they place emphasis on different skills and pursuits than the other races.  Kind of more along the lines of Skyrim's Orcs if that helps paint a better picture.