The lack of effective window flashing is the one issue that will cause future problems. (The author of the linked 2008 article says it cost him $15 and 10 minutes extra labour per window, so there's why you've got a strip of housewrap instead.)
The rest is mostly a sloppy tract build. FWIW, we've never used OSB for anything but wall sheathing. (Stems from when my building partner fell right through an OSB sheathed roof.)
Q