Sh.Amit Agrawal Ji,
Sir, I agree with your views expressed at serial nos.6 & 7 above. I further add that the date of taking ITC in books of Account (being statutory records) cannot be brushed aside.If ITC is taken in GSTR 3B and the same is reflected in 2A in Common Portal but the goods have not been physically received, then credit will not be allowed despite entry in books of accounts.
However, if all the conditions are fulfilled as per Sections 16 & 17, the date of taking ITC in books of account should be preferred to the date of taking ITC in GSTR 3B, regarding the time limitation.