Go to Settings → Profile. You can change your log in email in the Profile section. Remember that changing your log in email also changes the address to which your notification emails are sent.
To change your Bench password, go to Settings → Profile. Scroll to the Security section and click Edit. Enter and confirm your new password. Click Save.
Go to Profile → Settings. You can turn off email notifications in the Contact section using the Yes/No toggles.
Go to Settings → Profile. You can enable the option to have email notifications sent to all of the listed secondary user accounts under the Other Accounts section.