How to force email confirmation & 1 other Question

I plan on importing member accounts directly into the Profiles table.  That's fine, I already have a migration script.  However, I'm not 100% sure of the following :

1. How is the feature to force registration confirmation enforced? With a module? The default setup doesn't appear to require email validation and I don't want people registering with fake email addresses, nor changing their email address without confirming the new address, too.

2. If I import directly into the Profiles table without modifying anything else in the database AND the confirmation/welcome process is enabled (if it needs to be), does that cause Dolphin to mail ALL those imported people?  Meaning, is there a flag anywhere I have to set in the database to inform Dolphin that those accounts have already had their email confirmed?  + no need to send a "welcome" message...?

1.  To force email confirmation click on Admin>Settings>Moderation Settings.  Uncheck the box next to this line: Automatic profile confirmation without Confirmation Email.  This will require users confirm via email to be activated.  They can mess with their profile, but they won't have permission to do much else.

Thanks.

Do you know what would happen if I directly import member profiles into the Profiles table?  Is there a flag I have to set within the profiles themselves or another table to make sure Dolphin knows they've already had their email verified and to not send out a confirmation in those cases?

Oh come on. I've been asking this question for days......

How do we get the system to validate the email if a member changes it in their profile?