Profit below presumptive income for professional

If a professional is covered under 44ADA as per income tax and have receipt of around Rs 8-10 Lakh .

Q1: Is it mandatory to opt for 44ADA? 

Not Mandatory,  ..... but profit margin should be = or > 50% (i.e. deemed margin)

Q2. If due to intial year of growth profit is less than 50%, then is it mandatory to have tax audit?

As per sub-section 44ADA(4) ........ Yes, provided  ......  'and whose total income exceeds the maximum amount which is not chargeable to income-tax' ........

Please provide any option to save small professional from tax audit.

No need for audit, when your total income do not exceed BEL !!!