Hotel shops vary by client, as well as by MSC. The guidelines will tell you how/where you may or may not book the reservation. IF they do not want you to reveal your rewards status at the time of booking they will tell you. On the back end.... first, try to avoid wording the report in ways that would ID you if the situation was described to an employee. (One shopper's call for maintenance assistance was because she had set off the smoke detector by burning toast. Not the best incident to have used in the report, even though true.) Email the scheduler if something so unusual occurs that you wonder if it should go into the report or be handled outside of the report. Next, realize that hotel managers may or may not see the report, but it would rarely, if ever, be shown to a housekeeper or desk clerk. I have learned this from chats with MSC personnel from several companies. Valet.... a FEW NYC shops will require a car to assess valet and doorman services. Many just make that optional. In other cities, it is quite common to require that valet be assessed, but not universal.
A word about security observations. If any hotel staff member admits you to your room (when you claim to be locked out) without requiring ID, someone is going to be retrained, but only after an epic chewing out, IMHO. I have had this happen many times and always cringe when I have to report it. And, it means that I will be rating the site a 1 (on a scale of 1-10) in terms of likelihood that I would return or recommend it. And, yes, it HAS happened at a busy, upscale NYC hotel. Just realize that this is probably the most important thing that you were being paid to observe and report objectively.
Finally, take your time while on site; work your way systematically through the required interactions; do not cluster your necessary calls to the front desk. Make use of your phone's "notes" app to record timing and descriptions. If you cannot get a name say why in the report. Stay calm and carry on. When in doubt, consult your scheduler.
My goal is to depart the hotel with all of the report except the check out interactions, written.
Based in MD, near DC
Shopping from the Carolinas to New York
Have video cam; will travel
Poor customer service? Don't get mad; get video.