The Force is strong in this one...
You made the right call.
His second question is OK by me; shows me he'd possibly be OK with all the safety "rituals" associated with even a simple day VFR joyride... but his first question- ugh. And based on the other traits you mention, I'd make the same call you did.
Our glider club just got a new member, and he brought his cousin along the other Sunday. both on their motorcycles. The cousin, an easygoing , likeable guy, got my Spidey-sense going when he showed a lot of interest in the whole operation, yet also could not stop "joking" about how crazy we all were, and how he'd never fly in any of the aircraft seen that day, etc. He was joking, but not really. I could see that, even though I'd never met him before. I half-expected him to decide finally to take a hop, and I was damn sure it would not be me flying him.
Sample:
Him: "Are these things safe?"
Me: "Statistically, this kind of flying is about as safe as riding motorcycles."
Him: "OK, but...how high do these things go?"
Me: "Highest I've gotten here in these gliders was 6000 feet."
Him: "Wow, no way... not me!"
Me: "Actually, altitude is your friend, especially with gliders. Even if something's wrong, as long as the wings are still attached, you have more time and more options to get down safe."
Him: "Yeah, yeah, that makes sense; right. But you guys are crazy!"