Some, but not all, of these people seem to have genuine mental disorders which is why they act so weird and create risk. Other times they are just weird people with perhaps an arrested emotional development. Either way, it is important when dealing with such folk to try to discern if there is any mental illness involved, because that will have some bearing on how they should be dealt with. Also one must be careful to not stigmatize all those who suffer from mental illness. For not all mentally ill people are potential troublemakers in the church.
In my limited experience as a priest and in life I have found that the best and most healthy way to deal with those who create risk in small parishes and their weird behavior is direct confrontation - have one private meeting on my turf where everything is laid out on the table. After such a meeting, if it is on the rare occasion that the person has a mental disorder and is not seeking help, or he or she is just an antagonist or weirdo simply looking for a fight, the absolute best thing to do is to not engage that individual in any way.
The parish priest is a spiritual shepherd to his cure, and he must be ready to drive away from the flock all that would cause it harm and danger. It is not always pleasant doing this, but it must be done, and the needs and concerns of the larger group of people in the church who are focused on its mission and ministry must be given preference to those "attention seekers" who are simply at the church to use it for their own ends.
