Re: Urdu necessary for national unity
Eventually it will happen anyway. It has in Afghanistan, I tried warming up to a fellow Durrani from Kabul by speaking Pashto to him but he told me he only speaks Afghan Persian and that Pashto is not really spoken by the educated elite.
Actively banning other languages will not be a good idea because people will only rebel but like you suggested the use of other languages can be discouraged and regions based on ethnicity should be abolished.
Sadly the Islam drum has been worn out and close to ripping because of our own actions, now we need something to make us as a nation.