[vishnu_ks]

2) This is fixed. If you are running on-prem you can upgrade from master or wait till the next stable release. https://zulipchat.com/help/restrict-visibility-of-email-addr....

3) Zulip do support importing from Slack. https://zulipchat.com/help/import-from-slack. I don't think there is anything else we can do about this issue.