What if you simply said to her "It's been awhile, and I'm sure we've both done a lot of thinking about this. So tell me, (wife's first name): what are your intentions with regard to this marriage?"
I understand what you're saying about "going first," but the problem with that is, you can't deliver an "I won't abide X, Y or Z" speech when the other person hasn't even ASKED their way back into the marriage in any way. So this way, if her intentions are to end the marriage, you can say "Well, that's not what I wanted, as you know, but it's probably for the best as this isn't working for me, either" . . . and if she says ANYTHING about wanting to work things out, then you can say "I'm not sure HOW I feel about that anymore; clearly, X, Y and Z would have to happen for me to even consider it. I'm in a good place right now, and as much as I really don't want to divorce, the fact is that I simply can't go back to the way things were before, nor can I abide a third persorn in our marriage."
