Taqlid or taqleed (Arabic تَقْليد taqlīd) is an Islamic terminology denoting the conformity of one person to the teaching of another. The person who performs taqlid is termed muqallid. The definite meaning of the term varies depending on context and age.
No, they do not need to repeat them.
The concept of taqleed is indeed something important to look into, and although it sounds complex it is pretty straight forward.
1. Read about this topic from reliable sources, and educate yourself about the basics of taqleed.
2. Consult with a reputable qualified scholar about the selecting of a Marja'.
3. It should not take more than a few minutes for you to make the intention and follow the correct criteria for following a Marja' taqleed.
4. Do not complicate things by politicising your choice, or being influenced by hearsay, or looking for an "easy" Marja'.
5. Stick with mainstream, and do not be diverted to other ways.
It is not allowed to break the fast before the start of the night as we read in Quran (ثم أتموا الصيام إلى الليل ) (And complete fasting till night). This is the Quranic order which can never be challenged. This is for all people who have day and night in 24 hours.
If you live in a place where there is no day and night in 24 hours, then you need to either leave the place to another place where there is day and night in every 24 hours or to follow the timings of Salah of the nearest place to you. There is question at all to follow the timings of places which very far away from your place like Makkah, Madina, Najaf, Karbala etc.
The holy Qur'an says that believers should act upon knowledge: "And do not pursue that which you have no knowledge" (17:36). The idea of acting according to guesses and conjectures have been clearly rejected: "And they have thereof no knowledge. They follow not except conjectures, and indeed conjectures avail not against the truth at all" (53:28). Consequently, the one who is not able and is not qualified to deduce religious rulings should follow an expert and a mujtahid to learn the necessary details of Islamic law that are relevant to his life and situation. Not doing so would imply to follow conjectures of his own self or non-qualified people and this is condemned by the Qur'an. It is also possible to act according to precaution which implies to take the most precautionary steps and opinions but this requires a considerable amount of knowledge often difficult to attain for the ordinary person; it is therefore advisable for those who are not experts in religious sciences to follow a fully-qualified mujtahid whose knowledge has been fully established.
With prayers for your success.