When praying, how should one recite the Surahs? Should the Surahs be recited in the manner of 01-114? Or can it be recited randomly? 3) I would like to know about the ‘Isha prayer; i.e. the total number or Rak'ahs to be performed.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

It is not obligatory –while praying –to recite the Surahs in the order they are found in the Quran. It is confirmed that the Prophet recited in the same Rak'ah while praying late night prayer first Al-Baqarah [Quran 2], then he recited An-Nisaa’ [Quran 4], and then ended with Al-'Imran [Quran 3] [Muslim]

This is evidence that one can recite a Surah in a Rak'ah and in the following Rak'ah recite a Surah that precedes the Surah that he had recited in the first Rak'ah and that this is not dislikable.

But it is better to follow the order that is in the Mus-haf. An-Nawawi said: "It is more desirable that the person reads according to the order in the Mus-haf regardless of whether one is in prayer or outside it." [End of quote]

This was what the Prophet used to do most. He used to recite in Jumu'ah (Friday prayer) Surah Al-Jumu'ah [Quran 62] followed by Al-Munafiqun [Quran 63] or Surah Al-A’la [Quran 87] followed by Al-Ghaashiyyah [Quran 88]

The number of Rak'ahs in ‘Isha prayer is four. In the first two, the Imam recites loudly with Al-Faatihah and a Surah. In the remaining two Rak'ahs, he recites Al-Faatihah only. This is the consensus of the Ummah.       

Allah knows best.