1) no letter sign is required. This is a factorial sign not common punctuation.
2) Contractions may be used. See 9.3.3 of the Guidelines for Technical Materials.
3) You are correct in your transcription.
4) It may be that the person who prepared the Word doc did not have a math program (Math Type) to type the superscript properly. We are told to follow print but in this case I think I would transcribe it as it should be represented...use the superscripts.