Is audit u/s 44aa for home tution required for scenario

Sir,

Till FY 14-15 I used to declare earning in "Schedule BP" - against "Any other income not included in profit and loss account/any other expense not allowable (including income from salary, commission, bonus and interest from firms in which individual/ HUF/prop. concern is a partner)" 

And after that used to declare in P&L & Balance Sheet under "No Account Case" section. 

Details are -

FY 14-15: Schedule BP: 214000,  Income from other sources: 8753, 80C benefit: 43103

FY 15-16: Gross Receipt: 282000, Expenses: 32000, Net Profit: 250000, Income from other sources: 103865, 80C benefit: 93327

FY 16-17: Gross Receipt: 268000, Expenses: 35000, Net Profit: 233000, Income from other sources: 124556, 80C benefit: 100422

FY 17-18: Gross Receipt: 275000, Expenses: 35000, Net Profit: 240000, Income from other sources: 125728, 80C benefit: 102942

Note: Other income source are FD interest, Dividend from MF & Equity

So my question are -

1) Am I liable to maintain accounts as per section 44AA? If yes, what are the requirement?

2) For expenses - any thing need to maintain?

3) I am using ITR-3 - Nature of Business 17007, Is this ok to use No Account Case section (For assessee carrying on profession) of P&L & Balance sheet?

4) Is P&L / Balance Sheet required or need declare earning in schedule BP?

Regards,

Jigar