"should"= modal auxiliary verb used to give advice

as in "You should brush your teeth twice a day"

or to indicate something like "in the normal course of events"

as in " He should be there by now"

or "to express obligation or duty"....and I suppose this is the way you mean John.

I don't feel obliged to feel guilty and after over thirty years in a cult , I've given up being over-dutiful .Sometimes I even indulge in positively not being dutiful.

There is one "still-a-premie" who lives near me whom I introduced to Maharaji. I asked her recently if she regretted what I did ,or if she felt involvement in M. and K. had been bad for her in any way . She replied without hesitation and vehemently,that she felt quite the contrary. (She received K. around 1983 when the years of extreme devotion had passed  and has always done her own thing. )She's never had anything much to do with the organization and never pays to go to "events"...just says she's poor and gets in free.

I really believed in everything I did at the time.I didn't do a lot of the things that others were doing because I didn't like to.After the fundamentalism of the early years, I avoided all that as much as I could as it didn't suit my temperament.

I don't care what I "should" feel. I feel what I feel. 

" we were careless by not researching what we were joining carefully enough, and as a result of our carelessness, others were ensnared. "

In those days there wasn't the means to really do research.It was a different era.I've certainly never thought " O my God , it's all my fault.I didn't do enough research." The expertise about "cults" just wasn't out there.