but I am unsure whether I'd call him a predator (of course, language differences apply, too). That's just because I need words to express the predatory nature of people like Maxwell who prey on teens and YA.

What do you mean by this? Beahm was preying on a minor by sexting that minor and asking to meetup at twitch con. Are you specifically referring to people operating child sex rings? In either case, I don't think anyone else uses your ultra-specific definition. For myself, and I assume most others, pedophiles are merely a type of predator. For example, the show, to catch a predator, was about creeps sexting kids online. This is precisely what Beahm was doing so I don't think it's unreasonable to call him a predator.