I think your note is fine, and certainly reasonable. I'll be anxious to see how she responds.
My only other thought on this is somewhat the opposite of the "go slowwww" thing, but only in this instance: if she balks at the 50/50 agreement, and if it's true as you say that she seems HELL-BENT on getting free of you QUICKLY, even up to not retaining an attorney for herself, then I might advise you to put together a "sweetheart" deal that is more than 50/50 Kramer, and tell her THAT is the only agreement that you will move quickly on, and anything less -- now that she's being difficult (and this is assuming she IS difficult about your 50/50 proposition) you are going to DRAG YOUR FEET AS LONG AS YOU POSSIBLY CAN on anything other than the sweetheart deal.
I have seen occasions of wayward spouses SO anxious to get out of the marriage -- often with pressure coming from their OM/OW -- that they are willing to sign a sweetheart deal that greatly favors the betrayed spouse.
