1 In my view you can show firms income under section 44AD
2 partners salary and interest depends on terms mentioned in partnership deed
But as per income tax
Maximum interest is 12%, on capital
Salary in case of loss is upto 150000
Profit up to 300000 then maximum 90% of such profit
Above 300000 then maximum 60% (after calculating 90% on 300000)
But above salary and interest not allowed if you want to show profit in 44ad
Means in 92% deemed exp all exp are included already