Actually, that is pretty good. Obviously it's all speculative, but as a cogent assessment of the plot and where it could be leading, I think you've done pretty well.
I would agree that there are far too many loose ends in the game to say that the plot was meant to conclude with the ending provided in K2. Whether that is because there is a masterplan in Esse and a superlative to finish the trilogy plot in Posse, or because the game was created to have as little impact on either the first game or any possible future games, is still a moot point.
So, here we are: inter spem et metum.