Is the Welcome Email editable?
No, currently it is not editable.
Will this automatically be sent to the users upon creation of their account?
The Welcome Email is manually sent. All users can be sent the email at the same time.
Can I re-send the email if a user has misplaced the email or lost their login details?
Yes, a Welcome Email can be sent to any user at any time. It can also be sent to allow users who have lost their login information to reset their details.