As far as I know, the so-called intellectual guys were rounded up and killed by the Muhajir Biharis. As for the war in Dhaka, the City was full of machine gun sounds throughout the first night and probably 10,000 people were killed in the haphazard firing. After that, it was quite different as you have stated.I mean it’s not for me to say who’s actually intellectual and who’s not... people can look up
Many were just writers, journalist etc... there were some engineers and doctors and like I said many were cut off the list because they had friends in Pakistan military and just mind their own business in Dhaka.
Most of my family from both sides haven’t experienced any war to speak of... only one or two who actually went to fight could say there was war otherwise Dhaka was pretty secured until it’s eventual fall
About the total killing, I do not know about the real figures. I only know about two who were killed by the Biharis. One in or near Mirpur. He along with others were dragged out from a bus and were killed. Another, in Rajbari/Faridpur who was killed by the slaughtering of his neck by the Biharis.