Hi Scott!
I can't answer your question about the behavior of counts before relapse. I've had AA longer than you, but I've never successfully completed a Cyclosporine taper (I'm in year 7 of CyA therapy). And your counts destroy mine.. I could go back to my knife juggling if I had your platelets.
What I can tell you is that uncertainty reigns supreme with AA. Even with my super-long therapy, I can't tell you that I'm any more secure in my treatment than you were with your fast taper. I could relapse tomorrow, while you could go sans-relapse for the rest of your years. Such is the nature of our rare disorder. Certainly you have to take control of your treatment, and follow what the best practices are... but at some point you have to just come to terms with the uncertainty.
Anyway, that's enough philosophizing from me. I'm sure that other members whose situations are closer to yours will reply with more specifics than I have.
Take care,
Brendan