If its business class. Then yes it would. 1.5x miles.

The letter on the front which in this is "D" - is usually the booking code. And that on the BD site indicates that you will earn miles.

There are currently no fares in any paid business class on SQ that do not earn you miles. So I wouldn't worry too much about it.

Don't call SQ - you get the idiots at the Indian Call Centre. They cannot confirm anything that isn't in their notebooks.. as you asked them about earning miles on a frequent flyer other than Krisflyer. Next time ask if it earn you miles on Krisflyer. And if the answer is yes, then you can take it to be the same for BD.