1. I am a professional such as CA, doctors, lawyer, web-designer etc earning more that income tax slab. Which return should I file?

There are basically two types of return which is to be filed by a professional, either ITR 4 if he chooses for the maintenance and audit of accounts else ITR 4S if he do not choose the same. So, if you are maintaining your books of accounts and getting your accounts audited then you need to file ITR-4 else you have to file ITR 4S using presumptive source of income.