1. How to set up a pasword that is a minimum 6 characters long, 3 of which may be (but do not have to ) be numbers. Not possible as far as I can see. 
in the security assist wizard, go to the Manage pages tab, and click the pencil edit icon for the Configure Field settings option.
for the password field, you can make changes to the validation to change the Min and Max characters, the min and max letters, number s and specials.
to change this after the pages have been created, you need to edit the spry validation settings for the password field.
in design view, select the password field, Notice the blue bounding box that will appear around the field, click on that edit the spry settings. open the property inspector, you can set the all of the same minimums and maximums there.
you will also need to edit the Server Validation server behavior to edit the Entry Length validation for the passwrod field. Open the server behaviors panel, double click the Server Validation server behavior select the entry length validation and click the edit button to make changes.
2. Where to go in the system to set a page like the login page to go to a specific page if logged in successfully - or is the system supposed to log people in and then they find their way to a page by clicking a menu? At the moment. All I get is a numb message that I am logged in and the same page re-displayed.
on the login page, open the server behaviors panel and double click the Security Assist Authenticate user server behavior, you will be able to set the success and failure redirect options here.
3. How to change an error message permanently and save it in the preset.
unfortunately, the error messages cannot be changed in the wizard and saved a s a preset.
