I don't think he takes them too seriously. Like when cats get overly pushy when your preparing their food. He probably takes the point of view of Mohawk-sensei "it's just squeaking". I was hoping the pet-yus would make fun of the marisa for bothering Their geezer.
Not sure if the rank is fake or if the the breeder/shop owner has extremely questionable methods. The constant finger rape might actually dissuade yukkuri from wanting to get "married" since they put a lot into staying pure, the niceheads anyway.
I was thinking the same thing. And Reimu doesn't seem all that child crazy, maybe the factory is experimenting with Reimus that lack that "I need to be a mother and wife" drive.