The license is CC-BY-NC-SA. So you can share it (and derivatives of it) - with credit - for non-commercial (can't sell it) - under the same license. As long as you follow those rules you can do whatever you like. I have funny feelings about bringing in rules from another Tolkien inspired game. I'm still sorting that out. I requested access to your doc and will probably have a clearer mind once I read it. But again, the license allows you to do stuff, regardless of what I think. :)