First, cut of ties with Afghanistan, -Can be easily done but have you considered the impact on the local Pashtun economy?
second massive operation in Baluchistan, -Tried many times hasn't ended the rats
third investigate Iran/BLA connection and evidences needs to be made public- ISI do that all the time
launch protests against those countries who are involved in supporting such attacks, bring them to UNSC, - Futile , they just snigger and others give fake comfort
arrest all of those who collaborate and promote BLA/BRA agenda,- Just creates more enemies.
When you have traitors amongst the midst and enemies who ferment trouble and instigate indirectly it is difficult to eliminate this completely.
-There isn't much to trade, what is that Afghanistan can give you which can not buy from others? what you mean probably that Pashtoon's of Pakistan will riot and kill Pakistani's if the border with Afghanistan is closed which is a shame and question mark in itself.
Operation in Baluchistan? on the level of Rahe-Rast, Rahe-Nijat ? Zarb-e-Azb ? Kyber 1/2/3 ? when did that happen ? in which alternate reality ?
when, did ISI release evidence ? the connections were never made public or raise the issue with UNSC, target killing in Karachi , sectarian violence , attacks on LEA's Iran has their hands on many things inside Pakistan, dots are there for people to connect, but they don't want to because of sectarian reasons.
If cracking down on traitors make more traitors so be it, crack down on them too, you have to make a example out of people who commit treason, without the fear of state or law no one will stop doing whatever they are doing, ever wonder why in Islam there are punishments which has to be implied in public places? so people who witness the punishment they start fearing the State and their law. In Pakistan many people break traffic signals but in many other countries same Pakistani's don't, ever wonder why? FEAR of LAW and LEA.
Nothing is impossible, if a state wills it, no power or Organization withstand the power and will of state, once the state decide enough is enough, then no stopping them. Problem with Pakistan throughout its existence is that the nation is brave, hard working and Patriots but they been rules by sheep and traitors who serve others more then they serve Pakistan, this applies to both Political and Military leadership.