How do you determine if a marriage is in trouble? What would you do if you suspected that there were some problems with a couple that you know, and yet you also knew that they might not be completely honest about the situation? Just saying to them "is your marriage about to go in the tank?" might not be the most tactful way to approach it (though I know a few people who might think that would be acceptable!). One suggestion that could reveal much would be if you got the opportunity to come over to their home and have dinner with them. Just watching the two of them interact would be very telling.
Now, let us apply this principle in another area. How do you determine if a parish is in trouble? As above, you cannot walk up to the priest and say "is your parish about to implode?" There are probably a number of things that you might look for. Do the parishioners get along with each other? Is the priest personable? Are they financially stable? Yet, these things are merely some of the symptoms, and none of them really are the heart of the matter.
Do you want to know what the level of spiritual health is of a particular parish? Then, go to Mass when their pastor is the celebrant. What the priest does in the Mass will determine what the health of that parish is going be like. No, it may not have had the full impact if he has only been there a year or so, but it will reveal the direction that the spiritual state of the parish is headed (either for good or bad). The Mass is the heart of the Sacraments, and therefore it is the center of our relationship with Christ. If the Mass is done to entertain (which can only be done by breaking a large number of rules) then you can be sure that the spiritual health of the parish is going to go downhill, and that they will ultimately be moving away from Christ.
The Mass is not merely a "decoration" for the parish, like which color the drapes are at a home. No, just as the manner in which a husband and wife usually interact with each other will reveal where their spirituality is at, so also the manner in which the parish usually interacts with the Almighty God will reveal where the spirituality of the parish is at. The Mass is, after all, the primary place and event in which we interact with our Lord. All other things are secondary. If the Mass is being done reverently and with the intent of honoring and pleasing God, then it will impact the health of the parish for the good (though depending on where they are starting it may take some time). If the Mass is being done irreverently, or the rules are being broken regularly, then the spiritual health of the community will suffer for it (often, fairly quickly).
Things like the number of programs, the "happiness" of the parishioners, or the size of the membership, are not really proper gauges for the spiritual health of a parish. Programs really only tell how busy a parish is; regardless of what programs there are (a married couple can be very busy, but still have a rotten relationship). The "happiness" of the parishioners does not guarantee that they are finding their joy in Christ (I have known couples who were "happy" because they were enjoying something immoral). The size of the membership only tells you that they are able to get people in the doors, and not whether they are actually helping them develop holiness (there are married couples who have big families and lots of friends, and yet they hate each other).
So then, what does one do when he finds himself in a parish where the health is deteriorating? If he is unable to make a change (and most laity are unable; sorry), then he must do something to protect himself and his family. We can compare to a marriage situation again. If a marriage is in trouble the couple needs to get help, and you--as an outsider--need to be cautious about being under the couple's influence. It can impact your spiritual well being also. In like kind, if a parish is in trouble the bishop needs to step in (yesterday!), and you need to leave and go somewhere that God is honored.
Yes, this might sound like a drastic bit of advice, but to remain in a parish that is encouraging disrespect for the Lord and compromise in holiness, means that you are supporting that same thing (even if you are "personally against it"). There is a reason that the Catholic Church is structured so that a Bishop has many priests to serve in his diocese. Firstly, of course, it is so that every area has a priest. Secondly, however, it is also so that unfaithful priests can be found out, precisely by the fact that the faithful refuse to support them (because supporting them keeps them hidden!). Your soul and the souls of your families are at stake. With all the abuse floating around today, the faithful must "vote with their feet" and refuse to support those priests that are abusing the liturgy (amongst other possibilities).
I know that it may be difficult to drive extra miles to a parish with a faithful priest, but it is a small price to pay for holiness. If more people took a stand in this way, and those priests that abused the liturgy were left without a sufficient parish body to maintain the community, then the Bishops would recognize the problem and remove them from office. Some Bishops are willing to remove abusive priests, but many today are unwilling to do so (for one reason or another). As I have said before, it is often the laity that help to move the Church to accomplish genuine repentance. Will you do your part?