Your last paragraph is the most important example. If the employer brings in an employee in for a MANDATORY meeting, they must be paid.. Bring in a bag is not mandatory, and is not needed to do your job at Apple. If YOU decide YOU have to bring in a bag, then you do so, at your own risk, and on your own time. Apple has not mandated you bring the bag, therefore they are not mandated to pay you. I might add that Apple treats there employees well, including their part-time employees. The bag check is a minimal inconvenience.
As far as personal hygiene products and medications, the managers would most definitely accommodate those employees with such a need to be screened in private. The managers do not paw through your stuff. They take a casual glance in your bag, and then you are on your way. They are looking for laptops, iPhones, etc.. things that stand out and are of high value. There are many retailers who outright ban any personal handbags, backpacks, etc, unless there is a medical need.