ywnjudy,
I agree that risk is relative to perception in the society. This generation is much more sensitive to risk than previous ones, just because we reduced a lot of risks. At the time, when you could have been attacked by bandits, arrested by Romans or Soviets, etc, you might have disregarded some of the risks we are sensitive to. On the other hand, Gemora gets into long discussions about quote esoteric rirsk, like drinking cups in pairs, bring an example of a guy who lost count after 10+ cups, ended up drinking pairs, and gave an opportunity to his hating ex-wife to affect his mazal, so that he died after leaving the pub. As close as you can get to “do not drink and drive”.
So, if someone habitually was doing dangerous things at heights in explicit violation of a biblical commandment “build a fence over your roof”, not sure how simple those people you describe had to be…
Some sources on lashon hara distinguish between people who violate a well-known mitzvot, say kashrut, about whom you can presume they violate others also, and people who mistakenly things something is not an important mitzva (say, onaas devarim). you can’t presume that they would violate other mitzvos, only these ones.