Like all questions, the answer is "depends". :)

E.g. number of kids falling and breaking their arm will be larger, but the population is larger and medical care is better, now. So, overall, I think the risks are actually lower than when I was a kid running around unsupervised.

I don't know about the number of pedophile predators per capita, but I imagine that may be a roughly fixed proportion of the population. Kids now also have cellphones, so that's a lifeline kids never had in the past. So, I'd imagine that percentage would not really rise, either.

I would argue it'd be negligible. We live in a world fueled by fear, primarily because it's now so easy to hear about the edge cases. I used to blame newspapers for this, but it's gotten so much worse with social media. Now even the most obscure topic that would have not warranted the cost of ink is being broadcast to people, made all the more persuasive because of the anecdotal nature of the medium.

what makes you think they would go up? I was a latch-key kid growing up and by the time real risks of adolescence like sex, drugs, and driving came up I already had years of experience managing risk.

OTOH, when I look at how my ex has raised our kids I'm terrified that when they become independent they are going to get themselves into trouble and not have the experience to stay calm and get themselves out of it.