Discount, Incentive etc

II have certain doubts regarding certain GST issues. I will be very much obliged to you, if you can clarify the same.

I    One dealer has credits in the Profit & Loss account as under:

Turnover
   85000000

Discount Received
              2,50,000
Discount on Purchases Credit Notes from Suppliers

Volume Discount
              5,00,000
Volume Discount Credit Note from Suppliers for attaining the volume turnover

Cash Discount
              1,50,000
Cash Discount allowed for timely settlement-

Incentive
              4,00,000
Incentive received from certain suppliers for attaining the target

Breakages & Shortages
              2,50,000
Credit Note from supplier for the breakges & shortages- dealer in glassware etc

Interest received                   1,00,000        Interest on deposits bank

He has shown only the Turnover of Rs.8.50 Cr in his GSTR 1 and GSTR 3B.

All the above credit notes are non GST credit notes.

Now my doubt is

1.whether the above credits are to be shown as part of aggregate Turnover in his GSTR 9.

1. If it is not to be shown in the aggregate turnover, whether the same need be shown only in reconciliation of GSTR 9 C.
2. Whether for the above amounts the dealer has to pay GST and he has to show the same as taxable Turnover except interest.
3. Whether the proportionate credit of common ITC on the above except interest has to be reversed in case the above are non GST items.
4. The actual breakages and shortages cost are more than the credit note amount. As such can the same be treated as non GST item.

II .     One society has given a contract for construction of flats under the “ affordable housing”. I think the rate applicable to the contractor to be paid by society will be 12% in such cases. In case the same flats do not come under affordable housing the rate of GST of the contractor will be 18%.

III .  One dealer had not paid the RCM on GTA for the year 2018-19, which was noticed at the time of GST audit. The GTA is a registered dealer. In case he pays the RCM with interest on 10.03.2020 and avail the ITC in the 3B for the month of February filed in March 2020, whether the same will be an issue with GST authorities, who may say that the last date for ITC availment for 2018-19 is 20th October 2019.

IV . In case a dealer has given his property on rent of Rs.5 lac per month and he also collect electricity charges of Rs. 1 lac, whether it is ok in case he bill the rent taxable at 18% and Electricity charges 1 lac taxable at NIL, since electricity charges are exempt supply. Whether the department will ask for tax at 18% on electricity charges also taking the same as composite supply.