There are agreements as per the entry and exit of nationals on the international level on top of how visa issuances are done. However, local laws will apply; even the American embassy says so on its website: Arrest of a U.S. Citizen - U.S. Embassy & Consulates in Pakistan (usembassy.gov)
Freedom of speech, being international law, means nothing.
** Breaking visa rules with illegal entry is one thing; expressing your opinion about the Pakistan government and thinking a visa will protect you is a fallacy.
I have already discussed this with one of the top law firms in the U.S. and other legal experts. You can take them to international court, and nothing will happen.
This is correct. Only thing Pak visa will do is provide more $$$ to the establishment as visa fees are higher.
Brit/US consulate has limited power if arrested in Pak. I doubt that you will even be able to call the consulate from jail.