I am not Pashtun,but have been following politics of Khorsan region for long.
Historically Empires have controlled area from Lahore to Kabul,Durrani Empire on it's peak controlled area between Amritsar to Mashad,though we can't say same about Amritsar and Mashad but area between Lahore and Hairatan has got number of similarities.It would solve many of region security and economy issues.With all groups respecting each other a Federation can be created.
For rest of you said,Kashmir is disputed region,Pakistani and Indian Punjab are different only same language is spoken,one draws it's core from Islam and other from something else and above all Punjab has huge population of Pashtuns and Balochis out of 120 million total population other groups do make difference,such that current Chief minister of province is a Balochi speaking ethnic Baloch.Iranian Balochistan has low population,something which doesn't impacts.
P.S:-My idea is purely based upon using religion,historical connection,economy and security as drive for this initiative.
And about poll,Pakistani pres Ayub himself a pashtun offered Daud Shah about this but Daud shah walked out of it.