User blog comment:EmpyreanSmoke/Supernatural Q&A/@comment-168.169.25.92-20151101145543/@comment-24834479-20151103014515

1. It hasn't been reversed. The Angels are just using the portal to get back to heaven.

2. It is said that the speed is irreversible.

3. They will not heal over time. If they had a power source strong enough, they could use it to heal their broken wings.