Not clinically diagnosed with OCD; more of self-induced (former Soldier). LoL
To help with your water mains (you're using C3D!), use an Alignment for your pressure mains, with an Alignment Label Style that reads "W" for your Major Station text at whatever interval you need (+50, +100, etc)... Just be sure to set your read bias to something like 110. That way, it's always plan-readable.
Checklists are great; but a simple AcDb reactor would 'catch' newly created annotation objects and could attach an Object reactor to each (at drawing open too), such that if the *text's bounding box (+buffer?) overlap another's the Object's color is turned 'red', etc. just a thought.
This way, rated than isolation layers or printin hard olives to check an action item off your list, you can trusts that saving a drawing with no 'red' text is sufficient. It would allow you to focus more on design issues that positive negative space and overlapping labels.