I believe that the Gresham KH meets on Sundays and Tuesdays. I am not sure what "Irregular Attendee" means either, since I have never attended a congregation meeting before. It might mean that Regular Attendees are required to go to both meetings every week, and "Irregular Attendees" are sporadic attenders as you had mentioned above.
From the evidence that I have gathered, JH most likely converted to JW to marry AH. I noticed a photo from an unnamed local source, of one of JH's parents wearing a cross pendant. JWs do not wear crosses or have crosses inside their KH. So from what I have gathered, is it is likely JH, grew up in a different religion, or at least had a parent from a different religion. This might explain the "Irregular Attendee" statement. It is different if you grow up in a certain religion or belief system, than if you are newly converted. Growing up in one, and being exposed to it, means it has already been an integrated part of your life. Converting to a different belief system, or even a new job for that matter, requires you to learn a new culture, as well as learn how to operate within that new system. From a Psychological standpoint, there might have been problems with JH adapting to a new set of rules and expectations. Everything might have been different, from what he was used to growing up. There is a learning curve with any big change in life such as jobs, religion or even getting married. Within a two year time period, JH most likely changed religions, got married, had many jobs, went to school, moved a few times and I am sure the list goes on. "Irregular Attendee" might mean that JH had went against the system and refused to change, as he had shown in the other areas of his life.
One term that comes to mind is "Cognitive Dissonance".
"Dissonance theory suggests that if individuals act in ways that contradict their beliefs, then they typically will change their beliefs to align with their actions (or vice-a-versa)."
http://psychcentral.com/blog/archives/2008/10/19/fighting-cognitive-dissonance-the-lies-we-tell-ourselves/
If JH did not find his wife, new church, employers or even society in support of his actions (like child *advertiser censored*), then he most likely turned to the internet to find people that supported this type of dysfunctional behavior. It seems that JH created his own belief system, away from any church. He seemed to go to church when he wanted to, worked when he wanted to and spent money how he wanted to without regard for the people around him. With his new belief system, he most likely spent all of his time with his online *advertiser censored* and his online contacts that fed and supported his addiction. Both JH and his wife probably had little financial security because of this. JH went from job to job, and probably quit trying to secure a position as an EMT. Fantasy seemed to take over reality in JH's new (self-made) belief system.