I'm wondering if you ever got this working as I am in a similar situation.    I am new to tablets and I will say that android (and iOS I'm sure also) does a good job of buffering you from the file system.   But for me at least there gets to be a point where I want to muck with it.   I don't need someone else s cloud storage, I have my own, I just can't get to it from the tablet.

Oh and my NAS torrent client is a little different then yours, it has a web GUI for management.   I have not tried it yet, but as long as the browser supports Java script, I think getting the torrent going on the NAS client from the tablet is not an issue.   The problem I have is hot to get the file OFF the NAS.