Brother i understand what you are trying to say as population of Muslims in Pakistan is 97 % and its perfect for a society to be based on Islamic principles but there are few problems here
1) You have got three version (deobundi, Brelvi and shia) of Islam in Pakistan and some of them call each others mushrik and kafir if they dont agree with the interpretation of Islam of opposite side so which version of Islam you will implement in Pakistan?
2) You will not have 98 % percent Muslim agree with you about your perfect model of Islamic state. How you would deal with them? There are many Muslims who want to have selective Islam in their lives. I have heard many times that i am liberal , i am moderate Muslim and it took me some time to understand who is liberal Muslim. It simply mean i follow only selective Islam and only follow those parts of Islam which suit to my needs. Such peoples want to change islam according to their needs and they don't want to change themselves according to Islam so will you use force for such moderate and liberal muslim who will not agree with your version of Islam?
3) Lack of sincere leadership. You will need a ruler with great Islamic character to make Pakistan a great Islamic state and how will we get such muslim leader with character of like those of hazrat Umar(R.A), Hazrat Abu bakr(R.A), Hazrat ali(R.A) who sacrificed all their wealth for welfare of peoples and were walking on streets at night to make sure that peoples are not facing any probelms or they are not suffering because of hunger. The following are the historic words of Hazrat umar(R.A) over which he laid foundation of his rule:
By God, he that is weakest among you shall be in my eye the strongest, until I have vindicated for him his rights; he that is strongest I will treat as the weakest, until he complies with the law.
I will be harsh and stern against the aggressor,] but I will be a pillar of strength for the weak.