Thanks for all the advice and help, everyone. It's been a crazy few weeks and I think the drama has finally settled down. N and I took some time away from discussing anything relationship related...you know, to create a space where we don't have to be worried every 10 seconds about having yet another heated, all-night conversation. That time was genius.
It gave us both time to think and process all that we had out on the table...and N kinda came clean about being depressed, emotionally wound up and needed stability in her life from a partner. I have come clean on not being stable lately and have been actively trying to come out of my own depression that I never knew I was in. Our flailing in this space led to her search for stability elsewhere, but that search seems to have ended with N again finding that comfort in me again.
I know this doesn't change that she is kinked (I am too), is probably wired for poly (I need more time to ponder poly), but this does mean that for the moment, our exploration into very sharply changing our relationship space is indefinitely on hold.
I think this is the right move for us right now and I thank you folks for helping with new ideas and thoughts on the matter. I def will stay tuned to the forums.