You might also want to look at the Experimental version by @kku
(I do not recall the “Verify the Data” tool having Kari’s check for unmarried Families that have a “Marriage” family event. It might be the same as “Marriage date but not married”. But the date requirement might mean they are different tests.)
Check his might be be a good 1st step. He aready has written theGramps compatible test. They just have to be rolled into the interface and verify.py module.