I am a bit surprised by some of what is said in this thread. I have bought 2 SQ tickets on the web and cannot remember if I had to give passport info when booking. But I am certain I did not give passport info when buying tickets on SQ from a TA. I do remember however that if the name is not entered in the reservation system before pricing is done, things go awry. So I always make sure my TA enters the names before trying to price.
I also remember getting an award with BD miles on SQ and not giving them any passport info.