Q2. In his prayer does David seek to minimize his sins? To maximize them? Why does an authentic prayer for pardon require clear, unvarnished acknowledgement of sin to be effective?
No David just tells them like they are. This is how all of us need to come to God. After all God knows everything about us. Why would David even think it might work to not confess ALL his sins.
I know though I have tried to confess all of my sins there must be many I have forgotten about. However, my Lord knows my heart and is just and must except me for trying to remember and confess all of them.
Why must we confess our because, the Bible plainly tells us we MUST confess our sins. I beleive the bible to be the word of God. Therefore, if God says it that settles it for me.