There are three areas of the pastor's life which often occasion some level of confidence. The first is what he has going on with the circuit, region, district, and Synod, and all the people associated with those entities (circuit counselors, district presidents, various bureaucrats). The second is what he discusses with his pastor friends and colleagues, ie, the guys to whom he takes his troubles instead of all those clowns at Winkel who don't do things his way. The third is what is happening in the parish he serves. These areas overlap a lot, but they almost always start in the parish, which is where the pastor's wife goes to church every week, which is why things get complicated.
Some couples share pretty much everything (obviously anything heard in the confessional must be excluded from "pretty much everything"). There is an argument to be made for the safety of this approach. Things shared between husbands and wives are whatever is one step down from sacred. It can be done that way.
The danger of the "sharing pretty much everything" approach is that pastors necessarily get tangled up in some yucky things. It is often easier for the wife simply not to know about them, whether it involves a DP or a senior pastor or an elder or a choir director or any old parishioner. If the wife knows much about a personal conflict in which her husband is involved, she's probably either going to get mad and have trouble remaining civil to someone[s], or get scared or depressed and end up avoiding church. There is usually not a thing she can do to change the situation. Her involvement only ends up meaning sadness for her and no help to anyone else. So sometimes it is to the benefit of everyone for her not to know what's going on. Where then is nosiness? It is excluded. By what kind of law? Of tyranny? No, but by a law of common sense. That is something a pastor's wife should know and be OK with so that she does not make her husband's life any harder.
But no one likes the mushroom treatment except mushrooms, which wives aren't. One of my older wisers advised me that she and her husband resolved this struggle with the conclusion that anything that wasn't actually a Secret was something that he could and often should tell her simply as a social courtesy (especially true for the at-home wife with limited social inlets). That is something a pastor husband should know and be OK with so that his wife does not feel disrespected and left out.
There are times when the pastor's wife is the last person to know something everyone else knows (whether in the parish or among pastor-family peers). There are times when she accidentally learns something she wishes she hadn't (this also happened to me as a PK, so we need to help our kids through this question some too). Neither of those scenarios feels good, but it's only a big deal if the Frau Pastor makes it one. The pastor and his wife have to muddle through it with mutual trust, consideration, and respect. If I've learned anything, it's that being mad at anyone never pays off, and keeping my mouth shut when I'm mad always does.
Perspective and good humor go a long way, too. Once I was with a pastor-wife-friend when the husbands blundered into a super-secret conversation in our presence and had to hussle off to bewail the hour's catastrophe away from our virgin ears. My friend whispered politely as she wiped a pot dry, "They all think they're in the CIA, and they're just pastors." So they are, the dears. But they love their CIA, and there is nothing to be gained by begrudging them the joy it brings them. We would do well to remember that nothing makes a secret less intriguing than learning it how boring it actually is. I also know that when my husband walks through the room while a friend and I are discussing a sister-in-law's sister-in-law's retained placenta, we put the conversation on hold. Isn't it nice of them to return the favor?