I agree that the main keys here are slow, piecemeal progress, and lots of quality communication along the way. Feeling uncomfortable about something isn't about having a "right" to feel uncomfortable, as people feel what they feel, and don't choose their emotions. What you can choose is your words and course of action in response to those emotions.
In most cases, a relationship can go forwards and not backwards, so try to avoid a situation where you say, "I'm not comfortable with where things are *right now,* so please back it off a little." Instead, try to anticipate whether you feel up to handling the "next step," whatever that is, and giving your wife notice ahead of time.
It's very possible that things you don't feel up to today, you'll feel up to tomorrow. However, there's no way to be sure until that time comes. So as you said, baby steps, and much more communication than DADT.
Love means never having to say, "Put down that meat cleaver!"