If we want release of F-16, access to retired/stored airframes or third country stock we will need to offer some kind of carrot to the US. These days, reportedly, US is looking for air bases close to Afghanistan to launch drone missions if need be.
Now if we do agree to it, than the questions is what would we ask in return and how to package the acceptance, domestically and what would be the blow back from across the border.
Not doing so would result in what kind of fall out an from whom?
The advantages are obvious, if negotiated from a position of strength, release of withheld CSF, release of F-16's, & AH 1Z's, License to export double the number of LHTEC T800-4A engines (On Frame and spare engines) Third country transfer of F-16's and access to EDA land weapons and air crafts (Difficult to negotiate the latest version of AMRAAM) This is the obvious windfall. How much the US agree to all this depends upon how hungry they are and how much pressure India can bear upon them to not to do so.
The blow back will in the shape of political point scoring by the usual suspects, religious right will make a hue and cry with obvious political tint, and likely hood of Af Talibs facilitating Pak Taliban for cross border raids into Pakistan. To some extent, the last point can be managed. Financial squeeze and FATF censure will be a factor played in game.
What if we don't give access. US will then use overflights to target AF Talibans ( we will indirectly be giving them access in way) and might face the same blow back as described in the previous paragraph. US might then promote a more active role to be played by India in Afghanistan if they don't get basing rights in Pakistan.
In all this, what would be the reaction of China? How will they view the use of an airbase by US?
The permutation and combinations are endless and there is no simple answer to all of this. In the end Pakistan has to weigh its decisions keeping in view its short term and log term goals in the region. But above all see the benefits of a uni polar or a bipolar approach to its regional strategy.