The information in your TiM Profile is the information that will pre-populate onto your Startwork, and will appear on the Crew Lists for every Project you are connected to.
The information in your Account Settings does not affect Startwork or Crew Lists. Your Primary Email Address is the address you use to log in to TiM. Alternate Email Addresses are other email addresses you use, that can be connected to your TiM Account so any messages sent to those addresses will all funnel to your TiM Account. You can also change your password within Account Settings.