1 - The original business case for the F16s was about 110 fighters and the infrastructure was setup to support that many - but PAF is now stuck at a little over 70 odd. So - alot of wasted time/effort/money in infrastructure to support a larger fleet than what PAF has ..
2 - The F16s spent a large portion of their life under sanctions with limited spare parts supplies which comprimised their actual military value during those sanctions. Parts were begged/borrowed and Kaiser has been clear in his commentary of the 2001 standoff with India, there wasn't enough spare parts to keep up the temp of operations.
3 - They just about got a MLU upgrade to take them to Block 50 standards when the 18 Block 52's were bought.
4 - There is no possibility of upgrading to V standard/AESA radars for the last 1/3 of their life.
5 - The Block 52+ were never allowed to be sold with DRFM jamming.
6 - No AIM-9X were sold - even though they got the Helmet that would have allowed them to be used.
7 - No real possibility of purchasing new F16s ..
8 - No possibility of even 2nd hard F16s to get to the original number of 110 that PAF planned.
I am sure others on this forum can highlight more reasons than what i have listed above... but it should give you a taste of why I dont think the F16 platform has been "allowed to achieve its full potential.".
Yes - the country is safer with the current fleet than not having it - but that is different to saying the acquisition of the F16s have fullfiled the original plans the PAF had and then allowed the full potential of what the platform should have been able to offer had it kept pace with the growth of the platform else where interms of capbility growth and upgrades.
The F16 fleet in the PAF will now wither away, decay and die prematurely as it will not be "allowed" to keep pace with the overall developments and enhancements of the F16 platform being made by the manufacturer.
The initial purchase was for 40 aircraft with the potential for the PAF to buy an additional 60+ aircraft (and even more) if finances and situation allowed it. PAF never built infrastructure beyond the 40 aircraft that were put in service so I am not sure what "infrastructure" for 110 aircraft was set up in Pakistan.
#2, Pakistan had spares to last a limited amount of time during the late 90s once embargoed. What you say not only applied to the F-16s but to the C-130s, Cobras, TPS radars etc. etc. Had a war been imposed on Pakistan, we would have used what was at our disposal (the same situation as with F-86s and F-104s in 1965 and 1971).
#3, All of the Pakistani F-16s (MLUs) are flying at blk-52 spec. in terms of avionics and weapons integration. The 50 vs 52 difference is simply in engines. If you fly 50, you are on GE engines, if you fly blk 52s, you have Pratt and Whitney power plants. All of Pakistani F-16s are running P&W engines with spares.
#4, There is an absolute possibility to upgrade ALL of PAF F-16s to V/AESA standard if we get clearance from the Americans. After the MLU done on the older F-16s, they also got the Falcon STAR upgrade on the structure which prolonged the life of these F-16s to 8000 hours! This is enough hours to last for another 30+ years of flying so all these aircraft are prime candidates for the Viper upgrade. Not sure where you got the 1/3 of their remaining life information from.
#5, In the absence of DRFM module on the F-16, PAF has other EW assets that are dedicated for these purposes. As such you can get around this issue. It isn't a must have for individual F-16s in a strike package.
#6, Given the proliferation of BVR, HOBS AAM like AIM-9x solution, while good to have, is not a major issue. With AIM-120s in abundance, the F-16 fleet is well served by AIM-9L/M and AIM-120Cs. Also keep in mind that JHMCS (Helmet) is not just used for AIM-9x, it is a great platform for cueing not only surface attack munitions but also for BVR AAMs.
On 7 and 8, all of it remains to be seen. If no from the USG, then no, however a fleet of 76 MR F-16s, all upgraded, is not a slouch in any case and this will remain a potent edge for some time along with the AESA equipped platforms being inducted now.