Prayers in Kufa and Karbala
Question :

What are the rulings of the prayer of the traveler in Kufa and Karbala? Do they have the choice of offering full prayers? Is Najaf considered to be within Kufa?

Answer :

The traveler is permitted to choose between offering a full or shortened prayer in the “haair” of Imam Hussain (peace be upon him), and based on an obligatory precaution it is the place under the dome above the holy grave of the Imam and not beyond this area. This ruling does not include the city of Karbala at large.
As for Najaf, it is not within the city of Kufa, so this law does not apply and shortened prayers is obligatory on the travelers in Najaf.

Qasar Prayer
Question :

If someone travelled and he does not notice that he already reached the distance of 22.5 km or more, and mistakenly performed his prayers in full without shortening them. Is he required to repeat his prayers?

Answer :

Based on compulsory precaution, it is obligatory to repeat the prayer.

Missed Prayers
Question :

I was travelling for some days, after having missed some prayers at home. While I am travelling and shortening my prayers, will I make up for those missed prayers by praying in the shortened form or full?

Answer :

If these prayers that you missed at home, you must make up for those prayers as full, even when you are travelling.

Timing of the Prayer
Question :

If a person travels from one time zone to another and in the process he gains extra time when he reaches his destination, does he need to repeat the prayers if he is still within the time of that prayer?

Answer :

It is not obligatory to repeat the prayers in the said case.