Hello,
I do not know the answer to question 1 but for question 2, it is normal (not required) for an applicant for secret to be interviewed during the investigative process. It is not required if there is no issue but if there is an issue or clarity to be discussed then interview will be conducted.
I have a question to you, how do you know credit check has been checked from them or not when you said " Have not seen a credit check show up"?