I would like to say that what you try to say is sophisticated and well-mannered and perhaps a good mature outlook that PRC ought to have. But unfortunately that reality that is envisioned is far away from the above and also dangerous.
You mention about "funding electricity, roads, and cell phone towers in Pakistan" you have to add "in the interest of PRC military and control".
Also if you are making Pakistan the role-model for PRC Islamic policy that economic "motivation" will somehow make these group of people be pro-PRC and subservient to whatever PRC says would be most mistaken since you are making a huge supposition that Pakistan is of a certain standard. The only reason that Pakistan is enviable to PRC is because it is anti-India and not because it is looking for economic development.
Please remember that Pakistan has had a rich history of taking billions of dollars in aid from very rich countries and much richer compared to PRC and carrying out and foretelling to others what they think and not listening from others - afterall it is easy for the Pakis. Case in point - it is easy for Pakistan to behave like a terrorist pariah on others instead of like you say focus on economic development.
Next that will kill your whole argument(s) and preamble that you have put together are the following words:
North Korea.
PRC wants
Pakistan to be a North Korea and not a Dubai, Saudi Arabia and even a Islamic South Korea. Please do not promote and promulgate something PRC has not done before to others and wont do on to others and frankly is not possible for PRC to do. Are the North Koreans asking why Pakistan is getting more aid. Are the Pakis asking why North Koreans are getting better missiles. From what anyone is reading the latter is more true (military dimension).
One can say any sane pragmatic PRC leader knows the last people to trust and depend on is the Pakis. Also it is safe to say PRC would not make a reliant satellite country they want to control to be more
economic strong but to be more dependable. How do you make a country more controllable - make PRC to regulate, manipulates, and creates a hegemony for itself within the country of concern. Also there is far more important and better partners for PRC to invest and deal with and that is a fact - compare what PRC does with South Korea and North Korea.
Economic advancement and (any) occurrence in North Korea is controlled by PRC for reasons that you mentioned above to "curb" and "checkmate" others. Any economic advancement and occurrence in Pakistan ought to be looked at from the view point of PRC military motivation and wanting control Pakistan from within nothing else. The role-model for Pakistan is North Korea - Are the Pakis okay with that. Please do not assume the Pakis think the PRC is always good.
And thats why when the Pakis come and ask for payment and reward for "curbing" and "checkmating" the PRC will realise (and are realising) that Pakis have something that the North Koreans dont have. Also the character and behavior of Pakis is of a different blend to the North Koreans that will continue to ask for repayment for being anti-India. And also when PRC will try to explain to Pakis that they wants them to be another North Korea what do you think will be the response.
Further the thread that is on discussion here there are also words like ethnic cleansing and cultivation of patriotism due to internal tribulations that were mentioned before but have been put on the backburner because of the dastardly attacks. It is a fine-thin line that PRC is treading because the area is sensitive to scopes and domains that PRC does not have a history dealing be it through society and race (that will require it to line with the rest of the world) - but a certain neighbor of India and PRC is the PHD holder of such behavior. I really wish the PRC people and Chinese people are able to appreciate what is really happening and please go to the source of the issue that is the neighbor of India and PRC before it comes springs its tentacles to areas where there is no history of such things - you know why because it is easy for them.
Again condolences to the families it was a really shameful terrorist attack.