Apologies for the long post.
This is speculation based on observation: Out of curiosity, do you guys think Taihei might have a bit of OCD (Obsessive Compulsive)? I noticed that Taihei may have a couple symptoms. It's merely speculation and the "symptoms" could be nothing, but....
1. Cleaning, obviously. One of the first things people think of, with OCD, is being a "clean freak" (for lack of a better phrase). Taihei may just enjoy cleaning, but being a "clean freak" and wanting/needing everything to be tidy and in order can definitely be a symptom.
2. When Umaru convinced Taihei to go buy a car, Taihei was very clearly scared during the road test when he was driving. Another symptom of OCD is the fear of losing control and harming yourself or others.
Granted, you don't see Taihei constantly double-checking things or counting/tapping/repeating certain words to reduce anxiety. As I say, it could be nothing, but I just thought it might be interesting to speculate. One reason why characters can be so great is by how relatable they are or having certain imperfections. Like with Kirie and her social anxiety, for example.