Maintaining an accurate I&O keeps you from getting your butt chewed out by the cardiologist who is trying to manage his/her refractive CHF patient.
Seriously, you've listed very good reasons for maintaining accurate I&Os. We all know there are times when it is difficult but since CHF is the #1 re-admission diagnosis in hospitals, we *must* manage it for our patients' sake. If the patient "misses the hat," please double-hat the toilet. The cardiologist does not want to look at the I&O sheet and see "BRP" written in the output column. And daily weights are just as important.
(Oh, and pulmonologists hate it when the chest tube drainage isn't recorded....Oh, and surgeons hate it when the JP drainage isn't recorded....) You get the picture. Since I'm the manager, it's me they come to and say "Can you tell me why your staff didn't record yesterday's output?" And inevitably, the one patient that got missed was the one it was most crucial on.
I applaud your efforts in ensuring an accurate collection of data.