Yes. Each Priority Pass membership requires a separate Username at prioritypass.com. The Priority Pass app can access only one membership, but you can logout of the app and then login with a different Username. (It is not necessary to create an account at prioritypass.com to use the physical card, rather than an app.)

It depends how promptly the card issuer notifies Priority Pass, but it often seems to happen within a few days. The be clear, the expiration date embossed on the card is not relevant.

The Priority Pass terms for visiting Chase lounges are imprecise non-Chase Priority Pass Members will be able to use one visit entitlement per calendar year across the Chase Sapphire Lounge by The Club network in the United States. The word Members could be read to mean that each person can enter once per year, but I expect that their system will track visits by Membership. The only way we will know is when you try and report the outcome.