Hmm, interesting. It looks like the supposed non-linearity actually hurt the game,
Yeah, SaGa Frontier is far from perfect but I always enjoyed it. The idea behind it was solid, even if the game wasn't entirely.
A problem with the episodic choices you mentioned is that they become exponentially more complex as the episodes pile up, each with their own selection of choices. In a complete game, they are self-contained.
It depends on how you approach it, though. Most of the time in comics there isn't a ton of back-referencing going on unless it has some real relevance to the issue's plot-line (or unless we're talking about the convoluted messes pumped out by Marvel and DC).
In an episodic game series you wouldn't have to back-reference every choice every episode, you could just focus on the major choices or small choices when the player revisits a familiar area (for example, a brief dialog with an innkeeper remembering the Player visited the inn once before). You could dump the choice variables to a file each episode and at the start of a new episode retrieve only the variables that will be referenced that episode.
The main thing would be to avoid branching a storyline (where the major portions of the plot change depending on a choice or choices) because that is where the workload would would just grow and grow as you'd wind up having to make more and more branches.