Wholesale only setup

This is a wholesale site. Users must be approved and logged in to use the cart. If not logged in, redirect to a page to log in or signup for a wholesale account pending approval. In other words, guests/pending users should only have access to the home page, pages (about us, contact us) and login/signup page with no links/sidebars to the cart.

If a specific password is used, automatically approve the account.

How to assign to Wholesale group upon account creation pending approval?

Please advise how to proceed with the above.

Thank you.