Well, we reached a decision with the fireplace dilemma. In order to make the French door idea work, we would have to move another doorway on the inside of the house so we wouldn't lose space for seating. Right now it just seems like one more thing to add to a list that seems to get longer every day, so we just decided to stick with the original plan of a wall. And Greg is framing the wall even while I type this, so there's no turning back now!
I hope we don't regret it in a couple of years, but I think we'll be happy with it either way.