I'm on a reread through episode 5 and I'm already noticing things I didn't before.
First off Nanjo has memories from time when Kinzo" was suddenly selected to become the family head". Not sure if that affects Nanjo's age any, but people with time lines might want to look at that.
Another thing I noticed is that one of Krauss's contacts that supposedly got swindled in the moon tourism thing with him is a "Mr. Sonezaki". Higurashi references again...