What should be the ideal income tax slabs?

Rs. 18,000-20,000 per month is the basic salary required to support any family. And already profession tax is deducted by states on the salary. Add to this the compulsory ESIC deduction on a monthly salary of upto Rs. 15,000. The current income tax exemption limit is very low considering the inflation we have witnessed in recent years.

In my opinion, income of below Rs. 2,50,000 p.a. should be tax exempted. Rs. 2,50,000 - 3,50,000 should attract 7% tax. Rs. 3,50,000 - 4,50,000 should attract 15% tax & income above Rs. 4,50,000 must be taxed at 20%. 

Like people upto 2 lakhs should be exempted from paying IT. Have a flat 5% of tax on incomes between 2 - 10 lakhs, 10% between 10 - 20 lakhs, 15% between 20-30 lakhs and 30% above 30 lakhs. No questions asked ! It should be computed on your total annual income including interest, salary, gifts, rental income received etc. There should be no exemptions under any sections. In this way more number of people will come under the tax net with no room to show any deductions. Also there should be no TDS on any deposits or interest received. This way income tax records, collection, assessment etc. will get simplified.

I know a group of Doctors who were taking salaries, changed it is "professional fees" so that they can claim part of the rent, telephone, petrol bills, salary to asst, other admn exps as deductions and paying much less tax than before. Salaried class are the most sufferers. My idea is upto No tax upto 2.50L. 5% from 2.50L to 5.00L, 10% from 5.00L to 10.00L and 15% above 10.00L.