A property can be legal non-conforming because of the setbacks, or because of a
I agree with this with one exception - unless they've run into repeated examples of something, planning staff will rarely commit to a position on something like this outside of the specifics in the zoning code and other published development criteria. By far, the most common response will be "submit a proposal and we'll consider it".
In my experience, anyway. All RE is local so the OP's situation will probably be specific to that jurisdiction.