Yes. Once SAML authentication is enabled, there will be a checkbox to disable other authentications and you can disable other login methods, if necessary. Also, you will only be able to login locally via Super Admin.
No, currently only one IdP can be configured at a time.
At present, Transient, and Persistent are the Name ID formats supported for SAML authentication in Applications Manager .
In Applications Manager , you will not be able to use TFA when SAML authentication is enabled. This is because, the entire authentication flow is handled by the IdP when SAML authentication is enabled. TFA can be used only when signing in using Local or AD authentication.
If the IdP is not reachable and the other authentication methods are disabled, you can log in locally via Super Admin. If other authentication methods are not disabled, you can login to Applications Manager by using the Local or AD Authentication.
If the certificate is nearing expiry, Applications Manager will raise an alert after the user logs in. The Service Provider's certificate can be regenerated from the Applications Manager UI and uploaded to IdP and vice versa. After uploading, the lifetime of the certificates will be renewed.