Do you believe in a military solution to Kashmir?
Yes, but not the only solution.
Maybe not now, but as you mention, if investment in developing indigenous capability and production begins from now and we can produce weaponry at will across the spectrum, say, in 10-15 years time - PA would be in a position to deal with IOK?
Pakistan needs to strengthen its economy, not with temporary gimmicks like loans, but through a solid footing. If Pakistan had oil, the story would have been different. Pakistan has its biggest resource as its population, who need jobs and pay taxes through income taxes. IK has been raising taxes on business, who take out money from pockets of public. IMO, one of the places where Pakistan can have a good start is through investing in technology - be it defence related or non-defence. Curtail the imports, start exporting. Most of the higher education students go abroad, some return to serve the country, mostly don't. This means that other countries accept their talents/skills and give them a chance to progress. If Pakistan has the R&D in universities, the ability to design in industries and then factories to produce the item - any item be it laptop, car, truck, tank, helicopter, aircraft, satellite etc then the country can start to prosper. This is where the International relations will take a turn in favour of Pakistan. The 'nuclear' status is not working anymore in the international arena. West takes it as major threat. Pakistan could have learnt from China or South Korea or any other country which has an active enemy sitting on its borders. As an example, take Hyundai, it sells cars and tanks. Pakistani military is interested in national projects to produce military vehicles and aircrafts, but the non-defence sector is trotting along otherwise since decades. Honda, Toyota and Suzuki are being assembled, the local brand Adam is dead. While USA helped South Korea by all means possible, China did the same for Pakistan. One has to see what went wrong where.
As Pakistan takes time to prosper, India gets stronger everyday. Its also vice verca, it goes in Pakistan's favour too. This is why India has created a conventional arms race since Pakistan poses an undeniable potent threat in the arena of cruise missiles, ballistic missiles, second strike capability and nuclear weapons. India has to live with this fact. The speed with which Pakistan's nuclear arsenal increased has created lots of stir in India and few other countries. But you see, Nuclear deterrent saves Pakistan from another 1971, but it doesn't guarantee IOK becoming a part of Pakistan.
Pakistan's progress and its development does not have to revolve around freedom of IOK. Pakistan has to build its economy for itself, for its public, for its say on international diplomatic levels and to repair its tarnished image since early 2000s.
Wars and mobilisation require money. Its next to impossible to take IOK without a strong economy. Realistically, in next 10 years, PAF might have replaced all older aircraft with JF-17 and maybe could have got its hands on more F-16s, but in a war PAF will suffer F-16 losses and those would need replacements. A stealth aircraft out of Azm might have come up. If PA buys VT-4, it still won't have enough modern tanks to replace AK or T-80 or VT-4 losses except if any T-59 or T-69 are left in storage as replacements. If AH-1F are put in storage, then they will replace T-129 losses. PN will have to replace corvette and frigate losses. Replacements are necessary to continue an offensive. Replacements by older systems provides no edge in quality while Pakistan already cannot match India's quantity. Pakistan will look towards China or Turkey or any other country to replenish losses during the war and then after the war. This again means importing weaponry and technology. If all the components of a weapons system are local, its cheaper to produce. Next, when the required amount is produced, the factory can either go in slow or minimal production or start exporting that weapons system. When a war occurs, the factory can produce en masse through round the clock shifts. Through clever designing of machinery, the factories which produce trucks or heavy construction machinery in peace time could be able to produce MRAP and Tanks during war.
Pakistan has to manage speed and tenacity in military domain as well as manage diplomacy and narrative in international domain to gain a foot hold in IOK which currently Pakistan might not be able to do so, unless through some miracle. How many days before international powers intervene and ask both countries to back off ? 3 days, 5 days maybe 7 days. Pakistan does not have enough military muscle to capture IOK. Importing more and more weapons to gain that strength will further drain its economy. Using newly acquired modern foreign weapons does not guarantee victory over IOK.