Although I admire your drive to keep things fresh, trying to hard could mean that Ulm loses his authenticity.
My main principle is to avoid copying the old story and simply redoing what I did. In essence, I have decided not to re-read my old AAR, as to avoid being guided by it (either to avoid it or not).
I do recall part of its success was EU3's oddities. Particularly when I got Bavaria through spies, it really took off. Because of EU4's lack of strangeness (or at least lesser strangeness), I am trying to go other ways.
It's great, i just miss the "flag-life of other countries" and the Ferrara rivalry in the last chapters
I'll admit, duckie has replaced some of that. But I intend to portray more of the others. I don't think I will redo the old "What else is going on?" chapters of the original AAR, but rather portray other countries' stories a bit more intertwined with Ulm's story.
I learnt a lot from doing AARs for non-EU games. Their different focus and game mechanics forced me to think differently about the approach. Part of that experience is certainly going to come in handy for this AAR.