1) At the moment, anyone can signup with any kind of email address (no confirmation required) and get access to my content/product/service.
2) I require members to signup before they can get access to my content. If they can add a fake email, that completely invalidates the "gate" in "gated content." It's also important when sending out required emails like Terms of Service updates.
4) Enable an optional email verification step. Let me use my own email verification emails. Let a service like Mailchimp verify emails.