Numquam ponenda est pluralitas sine necessitate, you are putting too much unnecessary or groundless assumptions. Focus back to the story, your theory did not have enough evidence to support.
(Sorry for my bad English, I'm not native English speaker.)
First of all, mindless assumptions are reason why this site is popular

I will be doing it again, and I advise you to do the same - it is fun (well, at least to me).
Second of all, the quote you chose to reply - actually, there is nothing groundless in that argument. Nancy seems like Mary Sue, so, Caribdis can write whatever about her and it will be believable. He can leave it like it is now too, and it will be fine too.
Third of all - let me backtrack a little, my theory was just byproduct of defending cliffhangers - I just indulged a little too much in possibilites, but, my arguments were created to defend the story. In fact, I agree with you on your point, and that was my point too - people shouldn't assume anything about Orion "dying" or "somebody else will die in 0.10", because next cliffhanger could be anything, even something what seems ridicoulus at first glance, like Nancy being double agent.
And last but not least, there were same arguments when Acting Lessons were being written

people couldn't believe that story could be going in to dircetion of betrayal and death until it was a fact. So, never assume that creator want happy ending - he may not.