Credit Managment Questions

 We have a bare bones implementation started and had a few questions that we can't fully get clarified via the user guides or knowledge base so thought might be good to ask here in the community.  Any replys would be much appreciated.

• Automation Vs. Informative (What is updated else where vs. recommended to).
• Does/Can Credit Rating change in the customer master based on Automation rules or do you have to manually update it.
• Does/Can Credit Hold change in the customer master based on Automation rules or do you have to manually update it.
• Does/Can Credit Classification change in the customer master based on Automation rules or do you have to manually update it.