How can I remove a particular access level from the query?

I'm building a directory site for professional profiles. I'd like to be able to approve member profiles before they display on the site. I was thinking I could just use their access level to control this. So the first level would be "not-approved" and the next would be "approved". I could then just move users up into the "approved" level to have their profiles display on the site. Is there a way to remove the access level "not-approved" from queries?

Also is there a way to notify users about the change of access level through email?

Thank you.