Maybe we can agree that rules, guidelines, and counsel are necessary, but that denying the inherent applicability (by time, place, manner) of some rules/canons/regulations is ill-advised, but not necessarily "sin."

I agree, not only with what's quoted, but with the rest of your post, except to say that I don't think an avoidance of scrupulosity is a mark of situational ethics at all. To the contrary, it's something to which any good confessor is sensitive. I think we're in full agreement. Jesus opposed the irrational adherence to rules that had no bearing on loving Him or our neighbor.  

Seen in that light, even masturbation --- dare I bring that up again --- is a sin, as it objectifies women and lends itself to using another person for selfish pleasure, if only in the imagination. God help me; I'm agreeing with feminists! What's come over me? No. In all seriousness, this is how I was raised. I had an old-fashioned father who fully respected women, and a mother who fully 
cont.