Hygiene in Food Services

Here's an incomplete laundry list for further discussion (at your next friendly neighbourhood meetup with other food services folksies):

(1) Levels of hygiene: what activities are preferred, and what're not, and why? What's the scientific basis for this (if any)?

(2) Regardless of what's "really" clean or unclean, what sorts of activities are un/preferred because customers un/prefer them? Customers may believe anything they want, so to what extent do those beliefs affect your behaviour in food services?

(3) Regardless of what customers "really" believe - your first customer is your manager or boss, who may have preferred behaviours for staff. To what extent do you give your boss what she wants, regardless of (1) and (2)?

Meanwhile, it remains comical to me that blue nitrile (and just about any other rubber) gloves have been banned in front-of-house where I work, due to management assumptions about customers' probable assumptions about what staff have been doing, while wearing such gloves.