It doesn't really matter that Paul is such an anomalous hero, or that's he is in a more militaristic phase. The very least he can do for causing "OMG Angels are real" is put in some basic effort to dissuade people from doing stupid things on that front. He doesn't need a social reform plan, using clear cut words to explain "Don't provoke The Silver City" would help to prevent plenty of stupid actions. The rest he can leave to everyone else, and shrug at how some people are just too stupid.
Again, why is he responsible for people's reactions to Zauriel? Even if some people try to talk to the Silver City and get rebuffed, that only serves Paul's ends of getting people to stop identifying as Christians, sending them to a different afterlife where eternal punishment isn't a thing. And if someone is stupid enough to attempt
violence against the Silver City, they likely would have done that regardless of anything Paul said and likely deserve whatever they get, to boot. Just because Paul is a superhero doesn't mean he's obligated to try to save everyone from everything; one could easily argue that anyone dumb enough to try to contact the Silver City without learning more about it wouldn't be listening to the self-professed Hellenist on the matter
regardless.
Now, if it were
me in that position... well, I probably wouldn't have stolen the fruit in the
first place, but if I
had, I
would feel obligated to
try to stop people from doing something dumb, because I feel guilty for everything that goes wrong that I'm even tenuously connected to. But Paul isn't like that. He doesn't
do guilt, really, and isn't really interested in policing people who have multiple options and choose the stupidest of them. People who don't feel like they have options, who could be useful if turned? Sure. Random civilians who decided to try to contact an angel instead of going on with their lives don't qualify for that, though.
TL;DR: it's not a moral failing on Paul's part to not try to stop people from doing something stupid
unless it seems likely that it would cause major havoc. Which, given that Heaven's response to robbing the Garden of Eden was to send an angel to
negotiate rather than to smite, seems rather unlikely.