Quote from a mail that partly answers your questions:
What’s coming next in Proton Pass?
Password Sharing: You will be able to share your logins, secure notes, email aliases, and credit card information with other people, keeping your data end-to-end encrypted at all times.
Web app: This will let you conveniently manage your data or open Proton Pass in a full browser tab instead of the browser extension.
Desktop apps: With apps for Windows, Linux and macOS, you’ll have better offline support and better integration with your deviceʼs operating system.
You are not logged in. However you can subscribe from another Fediverse account, for example Lemmy or Mastodon. To do this, paste the following into the search field of your instance: !protonprivacy@lemmy.world
Empowering you to choose a better internet where privacy is the default. Protect yourself online with
Proton Mail, Proton VPN, Proton Calendar, Proton Drive. Proton Pass and SimpleLogin.
Proton Mail is the world’s largest secure email provider. Swiss, end-to-end encrypted, private, and free.
Proton VPN is the world’s only open-source, publicly audited, unlimited and free VPN. Swiss-based, no-ads, and no-logs.
Proton Calendar is the world’s first end-to-end encrypted calendar that allows you to keep your life private.
Proton Drive is a free end-to-end encrypted cloud storage that allows you to securely backup and share your files. It’s open source, publicly audited, and Swiss-based.
Proton Pass Proton Pass is a free and open-source password manager which brings a higher level of security with rigorous end-to-end encryption of all data (including usernames, URLs, notes, and more) and email alias support.
SimpleLogin lets you send and receive emails anonymously via easily-generated unique email aliases.
Update as sharing is now available.
2-4) See number 1 - exact functionality hasn’t been disclosed yet as far as I know.
Quote from a mail that partly answers your questions:
What’s coming next in Proton Pass?