If the staff is fine with doing the extra legwork and it's what the community wants I don't see the problem with it.
Huh. Well that was a nice non-answer.
Ok, lemme try again. In a vacuum I'd say no. Speaking as a total outsider and taking a perusal of your last few months' worth of postings in your off-topic forum, even for a small board it really ain't that bad. I've seen smaller forums do worse. Literally dozens of dead subsections just to have them, doling out mod status to all those dead sections (resulting a forum population that is like three-quarters staff), and forum "games" that were literally just things like "GET TO 1000 POSTS AS FAST AS POSSIBLE." Real face-palmy stuff. I mean, if that's your bag that's fine, but in a couple cases they were communities that wanted to be taken seriously.
You guys have one, catch-all off-topic section and a few active moderators, which is about where things ought to be at in a community this size. Looking from the outside in, this place is doin' a-ok. You're going to have a little chaff and some nonsense drift in. You can't really help that. Moderation is like dusting: You can be as obsessive about it as you want, but in the end the sum total of dust you're cleaning isn't changing, you're just making yourself go through the process of cleaning more often. Even if you do force Off-Topic threads to go through moderator approval first, that's no guarantee that the thread won't go to hell anyway.
EDIT: As a possible counter-analogy, moderation is like polishing a car. Keep up on it and a lot of the dirt and dust ultimately will just slide off your vehicle. In other words, maintain the standard. In time, people will adjust. Or leave.
So... basically, yeah, if the staff is fine with doing the extra legwork and it's what the community wants I don't see the problem with it.