Cash flows

Dear Sir

I still concern about some points related to preparing cash flows statement, but i do not know if they are correct. Kindly help explain them for me.

1. allowance for rcvbl: decrease in profit, NO effect on cash–> no need adjustment as bad debts (as those items already adjusted in increase/ decrease in receivable)

2. bad debts subsequently paid: increase in profit, increase in cash –> no need adjustment

3. accruals and provision: decrease in profit, no effect on cash –> add back to profit

4. prepayment: no effect on profit, decrease in cash –> deduct from profit
(however, In the text book, cash advance to other parties is treated as investing activities. If prepayment made to suppliers is also treated as investing activities)

Thanks a lot for your time!