Difficult to trust Pakistan - I don't know how many coups and constitutions they have had - every new 'leader/president/general' claims a break from the past after usurping power and old policies/laws/constitution becomes null and void. The only constant seems to be a virulent hatred for the 'other' - the Hindus/India etc.
So if General-X (who are we kidding - only a General has the power to do it) agrees to a peace proposal with India, firstly, there will be extremist sections of population that will denounce him for selling out (for these sections, anything less than a break-up of India and Pakistani flag on Red Fort will be a sell-out). Secondly, when this general is replaced by a new general, peacefully or otherwise, the new General-Y can simply claim that the last regime was not 'democratic' and any treaties they signed are null and void.
The word of Pakistan can be taken seriously only after they have continued without a coup for some decent length of time - say 20-25 years - and civilian authority, which has an interest in peace, is clearly calling the shots. As long as army, which owes its privileges to heightened tensions with India holds sway, nothing is going to change.