2. If a defendant would like to make a sanctioned payment to the plaintiff at the pleading stage (after receiving the writ and statement of claim), does he still need to admit the offered amount by filling in Form 16 or 16C?
Sanctioned payment and Order 13A admission are two different mechanisms with different stipulated consequences as mentioned above. While they are not mutually exclusive with each other, how to make use of these two mechanisms depends on the facts of your case and litigation strategy. You are advised to carefully consider the consequences under two mechanisms as mentioned before making use of any of them.