What makes you think he engages with them?

Some might be polite and somewhat knowledgeable (though most won't be either).

In the late 90s to early 2000s I was a teenager and communicated with various scientists and academics via email, some of which had something of a mentor role.

By those experiences I'd say someone like Alcubierre is more likely to engage young ducklings than, say, Michio Kaku.

make it so

No problem: https://www.youtube.com/watch?v=5q_z8BjiYng

This is one example of many. The original poster was just spreading FUD and saying nasty things about Alcubierre as a researcher. He gives talks like this all the time, he refers to his own work as a warp drive, he quotes and shows off Star Trek, etc. This isn't an issue of crazies trying to steal someone's research.