First time Traveller, had questions regarding customs duties and taxes.

Will be travelling from DXB to BOM, and planning to purchase 2L of Bailey's Irish in two 1L bottles at Dubai Duty Free. As on the website it says that alcohol above 2 Litres is subject to customs duties, will I have to pay duty if it is exactly 2L?

Also, in case my purchase exceeds the duty free allowance, am I taxed on the entire purchase or only the excess? Is BCD of 100% charged or 150%, as the site shows duties on only whisky, beer and wine and not liqueur?

Do I have to still declare the alcohol I bought because it's a dutiable good or can I walk through the green channel?

Lastly, as I'm over 21 but under 25, will Maharashtra state laws apply to my purchase, considering people aged under 25 can't consume hard liquor ( I have no idea of liqueur is considered hard liquor)?

Some of my questions may sound dumb, but I would rather be ridiculed by internet strangers than get fleeced at the airport.