You've got a lot of things on the table with your questions. Let me try to break this down.
Reg B applies to all credit applications and everything involved. The application and notification requirements of Reg B don't care if it's a new loan, refinance, renewal, increase, modification . . . .(etc.)
CIP exempts current customers that you have previously identified.
You use the word "renewal". This is a defined term in the regulatory world, so I'm not certain how you're using it. If you're satisfying and replacing Loan A with Loan B, then everything applies again. If you're keeping Loan A in place and modifying it, then some things apply but many things don't.
You can find a free Real Estate Matrix at our website that can help with these types of questions. Go to "Free Downloads" at the "Resources" page of our website: http://www.bankerscompliance.com/