My 3 cents is, it's a waste of time. There are plenty of forums online if you want sex, politics, a soapbox to rant on, guns, cars and everything else. IMO, if you want this to be a site that someone's 14yr old can read, then don't make this a site that includes a forum that's unrelated.
This is an amazing one-of-a-kind website, and I'd suggest paring it down to just what it's about. You've got 3 forums that cover the gamut from old appliances to look-what-I-found-estate-saling-today. That should be "it."
But it's your site, and you've got the vision for it, not me. My opinion is based on owning/running/moderating 3 online forums. A 5 year old could read our stuff....so could someone's 90 year old grandmother. Some might think, "How lame is that?" But you know what, it's actually kinda nice. Everyone's very nice to each other, there's no bad language, or even and representation of language, and no one's on a band wagon or soapbox. One group has been online since '97, so it seems to work.