Well I'm assuming a couple things here.

A, I assume that you calling yourself a "jack-of-all-trades" means that you are quick to pick up on new talents (with, perhaps, a small bit of instruction); cooking, electronics, strategy or logic puzzles, instruments, video games, crafts/skills, whatever. I'm basically the same way; I pick up on things quick once I decide I want to learn about them. But this in itself indicates a decent level of intelligence/aptitude and a willingness to try new things, so I would be willing to call you intelligent if you are a jack-of-all-trades as you describe. So you are probably at least smart enough to know that, without first gaining some expertise, you're probably not the best person to ask about complex subjects. That's one of the big parts of the Dunning-Kruger effect.

B, I think a big problem with fundies is that the bigger names out there are educated in unrelated areas, and think that their education means that they're qualified to speak in other fields where they've had no education. Fred Phelps comes to mind- he's a (former) lawyer and has written a few books, and so people cite him as an educated person, which I would somewhat agree with. But that doesn't make him qualified to speak in economics, sociology, civil rights, politics, or whatever other fields he decides he wants to jump into. But he decides that since he's got a little bit of education in some area, he's just as smart as the rest of them and knows exactly what he's talking about. This false sense of confidence is only made worse by the idea in his head that he's doing God's work, but that's not necessarily the only source of his confidence. But basically, if he were truly smart, he'd realize that he didn't know enough to make some of the claims that he does. (Another problem is when fundies get all their "education" from unreputable sources, like Christian Science academies, but that's another issue).

I know this sounds like a weird justification of the "We're smarter than them", so call this a personal opinion if you'd like, but this is how I see the situation with most "educated" fundies.