I'm not sure how many different ways you can ask about a rough idle, for example, but I think we're going to find out. Should we do anything for truly generic open ended questions that have no angle for a specific make/model?
Should we merge them? If so, how? All into one, or maybe let there be one per engine configuration (I4, V6, V8, ...) or manufacturer (GM F-Body, Ford CD3, ...)
The questions I have in mind are pretty much variations on "I have a make/model/year that's idling rough, any ideas?" and the answers are all variations on "Check the plugs, plug wires, coils/coil pack, fuel filter, fuel pressure, motor/transmission mounts, IAC valve, EGR valve, vacuum hoses, MAF, etc" with comments like "With the AC on?", "Is the check engine light on?" and "Manual or Automatic trasmission?".
Looking for specific examples, there is 1999 Mazda 626 Shakes when Idle. The OP states that the vehicle shakes when idle, states what they've checked / has been done to the vehicle since the problem occurred, and asks for ideas of things to check. The only answer that is really specific to OP's ride is this one.
I'll chase down some more questions when I get some more time...maybe it's not as bad as I'm imagining, I could be hallucinating from surfing too many forums.
For the record, I don't have strong feelings either way, I just thought it would be good to have a discussion about it.