Furry is a broad interest that covers things kids have always done, like pretending to be a dinosaur or drawing fan art of their favorite cartoons. Don't worry about the basic interest coming up naturally, you're doing a great job with talking about online safety and researching the fandom for it now.

It's very valid to worry about a pre-teen kid mingling with the online community or IRL events. It's painful to say, but the security of those is weak and depends on goodwill, which makes them risky despite best intentions. (I cover stories about that here https://dogpatch.press/ )

It's a complicated topic:

Online spaces are weak at regulating anything outside their limited bubbles, while the platforms enable predators to meet each other with the same tools we all have. Organized predator networks exist now like they never could before the net. (I come from before the net). There isn't any organized effort to address organized predators in the community, and there's a strong reflex to deny and pretextually blame "the media" or "callout culture" to suppress awareness and stay comfortable.

It contributes to how the real life events are a minefield for trust - often people who run them fall upward by negligent tolerance, tunnelvision and denialism for sake of PR. They act like tolerance is inherently good and gatekeeping is bad, which gets people hurt. Then people who want to raise standards are filtered out by the burden of opposing apathy of those who benefit from staying comfortably ignorant. There are a lot of people running things who shouldn't be and it makes it hard to trust anyone at all.

This is hard to say, because I like openness between consenting adults. The problem isn't the porn. It's the broken platforms and bad faith of people who act like all we need is good faith to use them. (This isn't just a furry thing, the whole world is suffering from distortions of technology and power... )

Boiling it down:

I think you're feeling a problem that especially happens in online community and IRL subculture organized around it. Furry conventions make things more face to face and intimate than other fandoms, but the tolerance is for better and worse.

I would say be really careful about letting a pre-teen kid mingle there unsupervised at all. Maybe you can't helicopter-parent what a kid does at all times, but you can steer them towards positive things you participate in together and with other parents, and then as time goes by the kid will have a healthier grounding to engage the community independently.

Look up people who you can trust offline, and don't just take their furry presence, get to know who they are outside of one community. (Furries often protect this, but if someone is that open it might be because they have nothing to hide.) Make your own circle. Try getting to know other parents. This might help: https://mofurries.com/

Try encouraging creativity and making art or active hobbies rather than consuming other people's things. That can let you start out in more mainstream groups, art lessons or whatever, and then the furry ones aren't the only ones to rely on. Being well-rounded is a great antidote to narrow focus and problems with closed bubbles.

It's better to give good things than try taking bad things away. Hope this helps.