I'm still wondering why the non-commissioned officers and crew don't seem to exist. Petty officers, crewmen (persons), every other Star Trek had them and technically, Ensigns are officers so they shouldn't be doing all of the grunt work. Wouldn't they be overseeing the crewmen doing grunt work.
I've been wondering about Tendi's specialization too. Wasn't she assigned to medical? Why is she floating around with Rutherford doing engineering stuff? Speaking of confusing, Mariner seems to have undergone a complete personality change. All of a sudden she wants to hang out with Boimler and is best buddies with him after giving him so much grief in the first few episodes.