Dark and Troubled Past: In high school, she was in some kind of accident where she lost several friends, and was herself gravely injured. One reason she likes Thomas so much is because he helped her through that awful time.
Neutral Good: Probably the nicest person on the entire staff, but she's not above some dirty tricks to get things done.
Beware the Nice Ones: Both comedic and serious examples. On the comedic side, it turned out that he was really good at Nerf battles. On the serious side, his anger is capable of shutting up Reggie.
Nice to the Waiter: The reason the other employees have hope for him is that he actually tries to treat them with respect.
Pointy-Haired Boss: Defied. Everyone expected him to be this, like his predecessors, and he does have occasional slip-ups due to a lack of practical experience. However, he actively works to get better; see Benevolent Boss above.
Reginald "Reggie" Watson Booth
Idle Rich: Working at the store seems to be his attempt at averting this trope. Whether or not he's been successful is up to debate.
Lawful Good: Despite his Jerk Ass tendencies, he really does seem to want to help people, and is probably the only person who follows all of the rules (including the dress code).
Lawful Stupid: Unfortunately, he doesn't have much in the way of common sense.
Lonely Rich Kid: It says a lot about his upbringing that Jo's "betrayal" from not sticking up for him hurt him so deeply.