ed - I don't know that I should venture too much re RC church, as I am not RC ,though I would hope that all Christians are following Jesus more than any pope or other earthly leader.
I don't see an issue with birth control biblically but if someone does see it as being sinful from their biblical understanding then that would be a problem to them, perhaps.
I don't see ignoring church directives as sinful if not directly biblical but I am probably not qualified to be definite on RC teaching.
therefore I would not feel sure about that in comparison to , what seems to me, to be more obviously sinful.