When reviewing Reg. E, section 205.11(c)(i.) it states that we will "provisionally credit the customer's account in the amount of the alleged error (including interest where applicable within 10 business days....."

Do financial institutions have to provisionally credit lost interest associated to a disputed amount to a checking account customer that has an interest-bearing account?

If the disputed amount caused an NSF fee, is that fee supposed to be reimbursed along with the provicional credit. If the dispute is declined the disputed transactions, interest and NSF fees would all need to be debited back to the cardholder, is that correct?

Yes, on all counts.

John's right. I like to say "Make it like it never happened".