Tax queries on let-out property having home-loan and co-owners

- Property A:
(i) Two co-owners - C1: 50%, C2: 50%
(ii) Two co-borrowers (Loan certificate 1 from Bank X)
(iii) Let-Out for all months
- Property B:
(i) Four co-owners, - C1: 25%, C2: 25%, C3: 25%, C4: 25%
(ii) Four co-borrowers (Loan certificate 2 from Bank X)
(iii) Self-Occupied for all months

- Property C:
(i) Four co-owners, - C1: 25%, C2: 25%, C3: 25%, C4: 25%
(ii) Paid-off i.e. no loan
(iii) Let-Out for all months

3) All interest is paid in 100% by C1. C1's bank account pays all EMIs (it's not a joint account)

4) All rental incomes (from all let-outs) are deposited into C1's bank account

5) Municipality tax and standard deduction (30%) is understood in calculations

Questions for C1's ITR-2, Schedule HP (Income from House Property sheet)
1) For property A
(a) can C1 maximize tax benefit by using proportional rental income (i.e. 50%) & using full interest paid (as per Loan certificate 1) ?

2) For property B
(a) Can C1 use full interest paid (as per Loan certificate 2) ? If not,
(b) Is C1 interest deductions limited to 2 lacs ? If yes, can other co-owners also claim 2 lacs each (upto limit of Loan certificate 2) on their ITR-2 returns ?

3) For property C
(a) Can C1 claim tax benefit by using interest payments u/s 24 and/or 80C ? If yes, is there a limit to 2 lacs ?
(b) Can C1 use interest paid to individuals (not a bank) ?
(c) Can other co-owners claim tax benefit u/s 24 on their ITR-2 returns ?
(d) Can we use interest paid for house property B to calculate income/loss of house property C (which is let-out) ?

Regards,
AVL