Increase in sales tax payable increases the cash because if at first place cash is paid then cash will be reduced but if payable is increasing it means cash is increasing as well and it will decrease when all sales tax payable will be paid.

if tax is paid then it will be shown in cash flow statement otherwise it will not shown in cash flow statement.

income tax liability is not part of cash flow statement rather it is part of balance sheet.

Net profit before interest and tax amount is selected for cash flow from operating activities and after that interest and tax is deducted while net profit before tax means net profit is adjusted for interest already while net profit before interest and tax means net profit is not adjusted for interest as well as for tax.

depreciation is a non cash item which have no physical outflow ... when depreciation is applied on tax cash flow it saves tax resulting in decrease in cash outflow