PL, I'm with Erin -- DON'T do the R talk. The best reason not to is that the WAS mind is torn and vacillating. Anything your H might say is something that he might change his mind about the next day.
His convo with your D was very interesting ... and very beneficial, in my opinion. His convo with your sister also shows that some family knowing CAN sometimes be beneficial. It all depends on the sitch and the person in question -- can they help or not?
With respect to your concerns about how the reconciliation process will work (or if it will work), I would advise that it's not wrong to think about those things, but take things a day at a time and some of those things will become clear eventually. For now, you know that you want another shot at a real marriage.
As for whether or not he's making progress, keep in mind that sometimes progress isn't linear and can come in large chunks. That's why patience is so important, which is good because you seem to have it.
The LORD is near to all who call on him, to all who call on him in truth." (Psalm 145:18)