My first reply considered the idea seriously, because ATeam is a serious poster, and never participates in the goofiness that some of us enjoy. After that, however, the goofballs chimed in, and what can I say? All work and no play, you know the rest - and a dull EO would be a ghost town, IMO.
I would not endorse any form of limitation other than those that already exist, ie: keep it civil, stick to the facts when voicing a complaint, leave the vulgarity to the CB, etc.
On vs off topic? That's a tough one, because threads are like conversations, which have a tendency to veer off on tangents sometimes. It's my feeling that if a strict "stay on topic" rule is enforced, the result would discourage people from posting for fear their comments would be seen as 'off topic'. Just my penny in the pond, (as DaveKC says).